Mostly.
> also, how popular is this theory in the physics community?
Not very. The fashionable way to think about this stuff is something called "decoherence" which really amounts to the same thing but phrased in different terms.
so if i were to do further research into this, I would use the keyword "decoherence"?
also not being a physicist, could I naively think this would be a good candidate for the "theory of everything"?
Decoherence, relational quantum mechanics, quantum information theory, the Von Neuman measurement model -- all of these turn out to be the same thing.
> also not being a physicist, could I naively think this would be a good candidate for the "theory of everything"?
No, the "theory of everything" refers to the unification of quantum mechanics and relativity. Completely different topic.