What are the consequences of removing known_hosts ssh files on mac

Question

The context is that I have had an ssh set up for GitHub for a long time and today for some reason I had an error saying that I have no permission to push or whatsoever I don't remember exactly the error message, but basically it said that I have no SSH set up and some googling told me that I have this key in id_rsa.pub, but this was not the case it turned out that it was in id_ed25519.pub. The thing is that I have already removed the id_rsa and id_rsa.pub, so I have lost ability to connect to some places (they were not many if any) but at this occasion I want to clear all the SSH keys on my computer and start with a blank card, my question is can I safely remove known_hosts known_hosts.old and config file, and should I even do that? Also I am concerned how is it possible that it suddenly stopped working / desynchronized on github's side and should I consider it as a security issue or it "just sometimes happens" because when I copied the contents of id_ed25519.pub and pasted again in settings/SSH and GPG keys it worked