My Deck is still in Q3 apparently but will probably get pushed back again. Will be picking up a couple of alternatives in the meantime.
Yeah netcode and infrastructure is really important, I've not looked into how Smash does it recently but rollback netcode has been wonderful in other fighting games. I really enjoyed Jump Superstars/Ultimate Stars online.
From what I know Smash uses P2P, which is horrible for a fighting game. Mario Kart 8 doesn't run peer to peer so I don't understand how they managed to screw this up so bad.
My Deck is all the way in Q4, let's hope they have more stock by then so I don't have to wait much, hope yours arrives soon.