I think that's actually already provably false if you're bloody-minded enough. I think the proof lies somewhere like Cantor's diagonalization but applied to reality, something like "if you could produce a model sufficiently complex enough to model the future perfectly it wouldn't fit into this current reality because it would require more than this reality's information"

I'm not saying it couldn't be locally violated, but it seems straightforward philosophically that each nesting doll of simulated reality must be imperfect by being less complicated.