It turns out there will be a Star Trek 4 after all.
According to Giant Freaking Robot, it was rumored that Paramount had scrapped Star Trek 4, along with the projects from Quentin Tarantino and Noah Hawley. The studio, however, has confirmed to Screen Rant that this is false.
Tarantino pitched his Star Trek movie idea to J.J. Abrams in 2017, calling it, "Pulp Fiction in Space" and described his approach as definitely being an R-rated one. Hawley, meanwhile, envisioned a film closer to the spirit of exploration from the original Star Trek series, but with an emphasis on the argument for why humanity has to come together to prevail.
These movies were rumored to be canceled, with the rationale being that all focus for Star Trek content would be shifted entirely to the television series titles.
Paramount has several existing series within the Star Trek universe on CBS All Access, including Discovery, Picard and Lower Decks, with the Pike/Spock show Strange New Worlds and a series about the Section 31 organization slated to arrive in the future.
Source: Giant Freaking Robot, Screen Rant