This is a hypothetical question. Obviously noone knows the answer but I would like to know your hypothesis.
What if Satoshi would move his coins to either Bitcoin Cash or Segwit2X. What would happen to the price of all 3 Bitcoin? Including Bitcoin Legacy
No he would never do anything like it, had satoshi's been here, he never would have led this happens, all this Bitcoin and segwit2x would never take place, again let's assume satoshi's is out there somewhere, why would he do it, when segwit2x has no actionable replay, that would be going against his own principles and that's not going to happen, Bitcoin cash is shit and again he would never go there. So your hypothesis would never really occur.