Except that that's precisely what some Copenhagen Interpretation guys actually wanted to say; that the collapse of superposition didn't happen two days ago. Hence S's large-living-object example. You want to be sensible, they (according S) didn't. Their "lack of sense" tends to force them to many-worlds views.

But Einstein and S's being sensible pushed them towards thinking entanglement couldn't be a real thing. Although their best default position is to toss up their hands and say that there's gotta be a non-local hidden variable we just haven't found yet. But there are no candidates, as yet. (Unless you like Bohm, I suppose.)