I don't play Genshin, but I watched Finana's recent stream. I take it Raiden literally doesn't remember him since he baleeted himself from history?
Yes, that's how Yggdrasil...err, Akasha works. Deleting yourself from the Tree's memories triggers a wave of memory rewriting that reverses any cause-and-effect happened before, although there IS some kind of corrective force at work that ensures the 'new' reality won't stray too far from the 'old' reality, because no matter how you rewrite it you still can't bring back dead people.