can ww now ult out of

Yes, his ultimate makes him unstoppable. If WW holds down Q, he is immune to displacements (knock up/down/back etc) as well, so he can Q through Veigar Wall if it is locked on, since Veigar's wall applies a knock down to hold you where you were when you got stunned. WW will still get stunned, but he won't be stuck on the wall.