Dormant franchises, even beloved ones, need the occasional rush of adrenaline. Interest in Bleach reignited when Burn the Witch and the new anime adaptation of the final arc were announced. Evangelion gets a shot of adrenaline every years from new projects, be it a new film or new dub. Sailor Moon never left public consciousness, but the Viz redub and Sailor Moon Crystal brought new eyes to it once more. Regardless of the product's quality, new blood means new life for classic franchises.
This is where the new Inuyasha project comes in. Yashahime: Princess Half-Demon is an upcoming sequel series that follows the children of Inuyasha and Sesshomaru on a brand new adventure. While there are those who are skeptical about the upcoming project, this might very well be what is necessary for this long-dormant franchise.
New Life with New Characters
Inuyasha ended in a manner which left little to the imagination. So much time was spent with these characters that there's precious little left to the imagination as to what could happen next. Without that sense of drive or conflict, there's no way these people could be the main characters again in a sequel unless it introduced an entirely new, even bigger threat for them to overcome, which by this point might feel slightly repetitive and redundant.
However, Yashahime offers a chance to continue the story of the characters we know and love without it being about them. We can spend time knowing what happened next to these characters without the story's core conflict and appeal focusing on a repeat of last time. Rather, we have new characters audiences can grow attached to.
This offers fans a new opportunity, since they can simultaneously see the old characters encounter new conflicts while the next generation gets a chance to shine. Like in Boruto, The Legend of Korra and Star Wars, this accomplishes two things: it keeps the old series alive in the memories of old fans and introduces new fans to both a brand new series and the legacy from which it comes from.
The Retroactive Continuity Dangers
The big risk with any new entry in a beloved but dormant franchise is the question of quality. Will it be good? If it's not, could the series retroactively damage what came before it? Will we see that something horrible happened to ruin the happily-ever-after our characters earned after hundreds of episodes and manga chapters?
This is one benefit to focusing more on the children than the main characters. Because this put some distance between the new story's protagonists and the old cast, there's less of a risk of seeing the old cast be ruined in some way. While there is always the chance we might learn Inuyasha and Kagome broke up after having kids or something, the series won't really linger in that negativity. Besides, a series like Inuyasha, which so greatly values the status quo, probably won't deviate far from said status quo.
Regardless, whatever happens in Yashahime will bring attention to a franchise that has remained fairly stable for years now. The merits of Yashahime and its new characters are hard to measure at this point, since little is known beyond a synopsis and character designs. The new characters might be great or they might be terrible. However, it is a little scary for long-time fans to learn what happened to the old characters they followed for years.
However, regardless of what is done, Yashahime will manage to revive the conversation surrounding Inuyasha. It's unlikely the creators will do anything drastic to the core group of characters, but even if they do, the original series will not go away. The prequel and sequel trilogies to Star Wars didn't ruin the original trilogy. Even if Yashahime is horrible, the original Inuyasha will remain.