That's up to Cuber, not American legal "scholars".
A Cuban is whoever Cuba says he is. And it's completely orthogonal to American law. Anything else would be a cession of sovereignty.
If Cuba were to make JCB a citizen, you could just go down to the consulate (in Canada, maybe?) and collect your passport. It would be up to you to accept or reject the "honor".
“Anything else would be a cession of sovereignty”
That’s how the law works in Cuba. Son of a Cuban born in Cuba, you’re a citizen.