Looks like owner of Ryujinx changed and now is developed by someone else? The top contributor for this is gdkchan, the previous owner and main developer. So this is not simply a fork, but changing ownership of the original repository. Is that right?
It makes sense, because what happened previously is that gdkchan got a message (or visit) from Nintendo to stop working on the emulator. That’s all. There was no cease and desist to the entire project, or anything like that (unlike with Yuzu).
As far as I’m aware the original repo wasn’t DMCA’d. It was just taken down by the original Owner after Nintendo asked them to. This seems to be why these new “hard forks” haven’t gotten taken down.