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).

Edit: Another hint that this is the original repository is, that a message is displayed that I have blocked a certain user who contributed to this repository. This message does not popup on any of the forks.