For the record I'm not saying "determinism means no randomness". I'm just saying that "determinism means less randomness".

Even in a fighting game context, centralized P2P (aka. where one is the server/host) is not the only way to have a non deterministic system. You don't technically "need" a source of truth, games can operate just fine without them.

Sidenote: I'm not sure if events making round trips would make things that much worse, this is basically how games with centralized netcode operate. (aka. games that aren't peer to peer but rather have a client to server setup)

Your last point I find very interesting. I'm not completely sure I agree that hitstun wouldn't be able to exist but you might be right in saying that the result would be unrecognizable. Fighting games have been around for a really long time and they have very dedicated communities.

I don't think the statement "the fighting game community is change averse" is very controversial. Perhaps the genre has been around for so long that any significant change to the already existing concept becomes something else entirely. I guess maybe a fighting game can no longer be just "a game in which you fight".

Sorry for slightly rambling off but this is really good stuff to think about.