John Romero is working on a new IP for a major publisher
While few details have emerged - an FAQ on the website states that "it’s way too early" to share more info - the move is significant as it will be Romero's first project in some time working with new technology, for a major publisher, and (presumably) with a decent budget. All of his recent games have either been self-published or independently published, and have mostly not been in the genre he's most associated with. His last FPS game was Sigil, a 2019 mod of the original Doom, built using community-created modding tools to create original levels. (While originally published independently, Sigil was eventually picked up by Bethesda and released as an update for the console ports of Doom.)
Some other upcoming projects for Romero include Doom Guy: Life in First Person, his autobiography expected to release January 10, 2023, and Sigil 2, a mod of Doom II similar to the original Sigil.