I do not know Oda's relationship to Tat. I do know I updated the forum on Lilith in One Piece. She is the sole survivor of the Egghead arc Vegapunk wise. The others will be reconstituted. The fact of the matter is Vegapunk bemoans York, who represents desire, and apologizes to Lilith, although not in person, over York's betrayal. This is a true tragedy and whatever allowed Lilith to be the one to join the crew for the next arc on is nothing short of a miracle. Whatever happens with Sinfest's Lilith is unknown.
-Russly