Since Alexei's body has not been found, we do not know what happen to Alexei.
If Alexei did survive and lived into his twenties, he might well have had a child.
If this is true, don't you think if a claimant came along who really was Alexei's son, that he has every right to make this claim?
Do not not slam the doors shut in every claimants face unless you know the fate of Alexei.
Until then, all of us should keep an open mind, or, as we say in Bear territory, don't climb into that silly old box where too many others are there pretending everything is solved and there is nothing else to learn and know and ponder.
AGRBear