Games take 3-4 years to develop and it was first talked about in 2019, so the timeline is about right, especially since this isn't a normal Multiplayer game by all accounts. Idk if they've started anything related to Part 3 yet (meaning if they have any script or anything), but even if they were to announce that game today, 2026 is literally the quickest it could release barring any setbacks that could push it to 27. This is just how intensive AAA game development is these days.
I want Naughty Dog to get TLOU multiplayer out, do Part 3, and then finally move on to doing a new IP completely. There are Uncharted 5 rumors though which could hurt my hope for a new IP.