Batman has changed in many ways over different eras of DC. With the ending of The New 52 era in 2016 along with the beginning of DC: Rebirth and the current era, Infinite Frontier, the Batman universe has undergone many changes. Characters have received restored or updated origins, new plotlines have changed dynamics between characters, but more than anything, Batman's rogues gallery has changed thoroughly.
Different lines in Batman's rogues gallery have been cast over the years, foes have become friends, and the revolving doors of Arkham Asylum have become the premier vacation spot for Gotham's most wanted, where old friends and colleagues that recharge, and plot their next extravagant plot against Gotham City and its grizzly protector. With one of the greatest rogues gallery of all time, there's no surprise there have been changes over the years to Batman's forage of foes.
8 Clayface becomes a hero
One of the biggest changes to the Bat-Family post-New 52 was the trajectory of the character that is Basil Karlo. Known as the villainous Clayface, Karlo actually slowly became a trusted ally of Batman, even joining the Gotham Knights program in the Rebirth run of Detective Comics.
Clayface's first attempt at heroism, however, was in the Batwoman run in the New 52. After fleeing into the sewers trying to escape capture, Clayface was captured by a group of cultists, who used his clay body to revive Morgaine Le Fay, but also giving Clayface short-term amnesia. Joining Batwoman's team to stop the enchantress Le Fay, this would have given Batwoman a great opportunity to see Karlo's potential to do good.
7 Harley Quinn hits anti-hero status
The New 52 can most likely be credited with Harley Quinn's meteoric rise to fame. Having been introduced in Batman: The Animated Series, Harley Quinn was a relatively known character, but only typically seen as a foil to the Joker. However, the New 52 started a massive character arc for Harley that redefined her character and brought her into the spotlight for DC comics, which would make her a commercial success.
After constantly being mistreated, manipulated, and abused by the Joker, Quinn became a member of Amanda Waller's Suicide Squad, where she renounced the Joker, finally getting the opportunity to strike out on her own. And while Quinn wasn't fully capable of breaking free of the Joker's manipulative hold on her, the character development she went through in the New 52 was integral to her being able to rid herself of the Joker in DC: Rebirth.
6 Joker knows about the whole Bat-Family intimately
The Clown Prince of Crime has always had a very personal relationship with the Dark Knight, but after the New 52, it seems as if Batman and Joker have become even closer. After a temporary hiatus from Batman's life, the Joker returned in the New 52 in a big way, with the Death of the Family storyline shaking the core of the whole Bat-Family, as Joker terrorized each of them, revealing that he was very much aware of the secret identities of all of Batman's associates.
While it can be assumed that the Joker deduced Batman's secret identity years ago, it always seemed apparent that the Joker didn't care about who was under the cowl, and that he was more concerned with the Batman himself. But after the New 52, and the following Three Jokers and Joker War events in DC: Rebirth, it seems that the life of Bruce Wayne is very much of personal interest to Batman's greatest foe.
5 Bane, Forever Evil: Arkham War
During the Forever Evil event, the Crime Syndicate of Earth-3 invaded the Prime Earth, declaring that they had killed the Justice League and that the Earth was theirs for the taking. As it should be expected, chaos quickly fell upon Gotham, with the super criminals splitting up territory in Gotham City. But in an unlikely turn of the events, the greatest threat facing the supervillain uprising in Gotham City, was Bane, of all people.
Wanting to take control of Gotham himself, Bane would lead an uprising of inmates from Blackgate Penitentiary against the supervillains, even donning a makeshift Batman costume of his own in order to strike fear into the others. This attempt would ultimately fail, as Batman would return and restore order. But the Arkham War event would flag Bane as a serious threat to Gotham City, a threat he would follow through on in DC: Rebirth's "City of Bane" event.
4 Flashpoint Batman joins the rogue gallery
The Flashpoint universe re-imagined the DC continuity in one of the most famous Elseworlds stories in recent history. In the pre-cursor to the New 52 retcon, the Flashpoint universe introduced a new version of Batman, only it wasn't Bruce Wayne under the cowl, but his father, Dr. Thomas Wayne. After his son Bruce was killed on that fateful night in Crime Alley, Thomas Wayne donned the cape and cowl, and as Batman was significantly more aggressive, even using pistols as part of his arsenal.
While this version of Batman wasn't seen throughout the New 52, in DC: Rebirth, Thomas Wayne managed to find his way into the Prime Earth, wherein a strange turn of events, he joined forces with Bane, and worked to help ruin Bruce's life and taking over Gotham City, claiming that he was "helping Bruce become a better Batman". One of the strangest parenting decisions in recent times, which lead to Batman's father joining his rogues gallery.
3 Black Mask kinda falls off
In the pre-Flashpoint DC Universe, there was a large power vacuum in the criminal underworld in Gotham after Joker left the city. It was Black Mask who eventually claimed the spot of Gotham's head honcho, building his business right under Batman's nose, and exerting his dominance on the criminals of Gotham. He seemed to be an almost unimpeachable force, even killing Stephanie Brown.
Revamped for the New 52, Black Mask was given the ability to exude a kind of mind control over people through the use of his mask. However, this also led to him becoming increasingly dependent on the mask, going mad, and becoming addicted to having it. While still a crime lord, Black Mask was significantly less of a threat in the New 52 and Rebirth, which was disappointing after seeing his immediate rise to power and the grip he had on Gotham pre-Flashpoint.
2 Court of Owls goes quiet
One of the new additions to Batman's rogues gallery during the New 52, the Court of Owls was one of the most exciting story arcs in the whole era. The discovery of a secret society working in the shadows of Gotham was interesting enough, but to add to it the Court was made up of Gotham's most influential and powerful members of high society, which added a whole new dimension to their villainy, especially considering that it would be assumed that the Wayne family would be included in their ranks.
But after Batman foiled their plans to take over Gotham, the Court of Owls disappeared back into the shadows of Gotham after the New 52 ended. Without any main plots seen in DC: Rebirth, fans are still waiting to see more from the Court of Owls, although they are seeing plenty of Talon, the Court's main enforcer, who happens to be an ancestor of Dick Grayson, also known as Nightwing.
1 Less costumed villains, more public/government threats to Batman/Gotham
As time has gone on, Batman has come to be seen as a symbol in Gotham City. After decades of fighting clowns and penguins and criminals of all sorts, he's come to represent something to the people of the city, but that message has sometimes been misinterpreted by citizens of Gotham. In recent times, Batman's public perception has dwindled, leading to many seeing the Bat as a curse on the city of Gotham, believing that he himself is provoking criminals in the city and that he is the reason why things haven't improved in all his years of crime-fighting.
Across the New 52 and Rebirth, it seems that Batman's public approval is starting to drop drastically, which has led to the introduction of characters such as Gotham Girl, the Colonists, and even most currently the Magistrate and their Peacekeeper program, it seems that a reoccurring theme has become questioning and criticizing Batman's actual role in Gotham and how effective he actually is, with even the GCPD turning on the Dark Knight and his associates after years of working together.