And the USSR collapsing and the effects it had on Cuba after they adopted it proved him right.

Why would that be true? I dont really view the collapse of the USSR as really being about the collapse in material conditions - there is a reason why the collapse of the USSR is seen as a big deal due to the shock it did to the at least livable conditions prior to the rug being pulled out.

I always saw the USSRs collapse more to bad foreign policy honestly, overextending into Afghanistan was the primary one but id be interested to hear otherwise.

I dont think this necessarily vindicates his view on those specific merits