You are reaching. I'll give you the knee move, but the uppercut isn't even the same arm/posture.
Thanos counts as a 100% new character in my book. His gameplay is not at all similar to MSH or MvC2 Thanos, and I've spent a LOT of time with both.
It is so similar, the only way to not call it similar, would be to call it identical. Which, given the position of the not-attacking hand, is not the case. But dammit if the posture of the attacking arm is not a close approximation. It is very clearly based on his Marvel Super Heroes sprite. As are the other two [posted attacks]. The emperor ain't naked, but he damned sure ain't wearing all new threads.