There are always infinite interpretations of everything.
But the "no hidden variables" theory is the most popular and well tested theory about whether things have a state before we measure it. And it postulates that they don't.
It's not tested at all. No local hidden variables is just a priori true though. It's not part of any interpretation. All of them are subject to it. This is irrelevant though because there are alternatives to local hidden variables like pilot wave theory, the so-called many words interpretation, relationalism (i.e. inherent nondeterminism) and there's no way to test between any of them.
But the "no hidden variables" theory is the most popular and well tested theory about whether things have a state before we measure it. And it postulates that they don't.