We usually call those altcoins, so this isn't anything special aside from them wanting to market themselves as as relevant to Bitcoin. IIRC I had mentioned that something like "Bitcoin Original" would pop up eventually even though it's based on nonsense.
unless everyone switch to that fork, especially miners and merchants, at that point you can not call it an altcoin anymore
it is very unlikely that the vast majority of bitcoin users will switch to this, as well as merchants and services already adapted to the current fork.