According to an official statement on Ryujinx’s Discord server, developer gdkchan was contacted by Nintendo and they were offered an agreement to stop working on the emulator project, and while the agreement wasn’t confirmed yet, the organization has been entirely removed.
as of now, nobody took the place of yuzu devs, for example
suyu (the most famous yuzu fork) got just 50 commits in the last 6 months and are almost all of them are tiny changes to the readme where they only change the discord link or just memes