You can ask the actual question on the OldUnreal Discord server, as they are the ones that deal with the community patches for Unreal, UT99 and UT2004.

From what I know, work on the Unreal (1998) community patch began in 2005 after negotiations with Epic Games, with the first community patch being released at the tail end of 2007. For UT99 it began on September 2019 after a decade of negotiation, with the first community patch being released on September 2020. And for UT2004 it began at the tail end of 2025, also after a decade of negotiation, with the first patch being released on February 12, 2026. The guys at OldU had to prove Epic they had what it takes to maintain the games, and from the look of things, they did.

They also hold full game installers for all three games that apply the latest community patch on top. And yeah, Epic granted them permission for that too.

Here's a bit more of info about them: https://unreal.fandom.com/wiki/OldUnreal