Wouldn't acknowledgment serve as well to confer citizenship? It would in the US, and it certainly would serve to establish that his legal fatheer was not a US citizen.
Absolutely not because their citizenship..at that time..for these circumstances.. was based on a MARRIAGE.
It would require a judgment call.
As I have said multiple times..it could be that the powers that be would have decided to give him citizenship based on a variety of factors...but that is a judgment call..not automatic citizenship. It would require a process, documents, arguments, proof, etc.
Or perhaps a few wheeling and dealings behind the scenes in Spookville....