Woah that is quite a theory!!

I looked on her page and didn’t find such a discussion, but anyone is welcome to investigate better than I did and REPORT BACK.
But I think the confusion might have come from the fact that Amel mentioned something about Nicolas and Lestat’s calling their feeling of connection "Our Conversation,“ and that Amel basically wanted to have that same thing w/ Lestat.
It is possible that Nicolas is still undead and kicking around. We have no real definitive proof that he’s dead dead. We have other characters returning as ghosts and let’s be real here, among them is one we REALLY DIDN’T WANT/NEED BACK omfg, and Lestat handled it like a real trooper when it might have driven anyone else in his position completely bonkers
Frankly, I don’t think Nicolas would have wanted to be that enmeshed w/ Lestat after their very unfriendly breakup. Would anyone want to climb into their ex’s body and stay there for all eternity? *shudders*
Possible TVL spoiler ahead.
Nicolas can’t really be Amel bc Amel was around during the Egyptian era in order to start the whole vampire origin story. Nicolas wouldn’t be born for another few thousand years.