The Bethesda game total conversion is a difficult path not for the faint of heart.
First reported by DSOGaming, the Project Mojave Revitalization team is calling it quits after its first (and last) release. PMR was a continuation of the ambitious Project Mojave mod to bring areas from New Vegas into Fallout 4, with the original PM devs themselves having hung up their spurs after an early access release in 2021.
Project Mojave is not to be confused with Fallout 4: New Vegas, a project aiming to do a 1:1 remake of the 2010 Obsidian classic in Fallout 4's shinier, upgraded Creation engine. The idea with Project Mojave was to present New Vegas during the time period of Fallout 4 and after the end of FNV -- a tall order given how many different endings that game had, but PM seems predicated on an NCR victory. Project Mojave itself saw no further updates after November 2021, and the PMR dev team led by WolfeMan2077 implemented its continuation as a separate project requiring installation of the base Project Mojave.
PMR's first and only release fleshes out a selection of four new areas focused on the outskirts of the Strip, with the most notable to my eye being "Fremont," the time lapse version of Freeside which has become the capital of a new NCR state in the Mojave. The original Project Mojave release included roughly a quarter of New Vegas' map, focusing on the interior of the Strip itself and some areas to its east.
Uploader WolfeMan2077 said "it's been a long road, but I think this might be the end of it" in the PMR description, and describes himself as the "former project lead" of PMR in his Nexus bio, so this looks like the end of the line for Project Mojave -- at least until some hungry modders who haven't had the innocence beaten out of them in this cruel life take up the mantle for Project Mojave: Re-Revitalized.
The road to hell is paved with Bethesda game total conversions: Many die quiet deaths, like Morroblivion, which appears to remain in a perpetual v066 -- playable start to finish, but buggy and not fully playtested, its host game practically as retro as Morrowind itself. The much anticipated Fallout: The Frontier managed to hit release, but was heavily criticized for the quality of its writing and the predatory nature of one of its writers.
On the more positive end, The Fallout: London devs seem to have largely pulled off their massive undertaking, and Morrowind's Tamriel Rebuilt is a bit of an institution, slowly, surely adding more of Tamriel's mainland to the 2002 RPG over the course of 20 years. Skybliviion looks like a professional-caliber remake of TES4: Oblivion, and seems to be marshalling a sizable, well-organized team to do so. And I'm rooting for Vampire: the Masquerade - Reawakened, which began as a remake of the 2000 VtM RPG Redemption, but is now doing its own thing after facing potential legal challenges. One cool outlier is modder cc9cii, who's working to get many of the Gamebryo-Creation games working in the open source OpenMW engine.
For your New Vegas in Fallout 4 fix, well Fallout 4: New Vegas still appears to be in active development as of November 2024. I'm perfectly happy with the original game (plus a few mod fixes) though. And you could always truly embrace the New Vegas life and move to the real life Goodsprings.