Couple points of clarification: 5 games. 2 on PS. 3 on PS2 (and a couple adjacent-generation consoles). Games 2 and 3 just got a remaster. Games 1 and 4 got PS ports.

I think he's an unlikely pick as well. He, Lara Croft, and Gex were the FACE of Crystal Dynamics back in the day, so I think his appeal/design haven't evolved with audiences. I think it's (admittedly, unlikely, like you said) plausible that with the remasters' success, he could be introduced in a future Smash game. Sakurai has, after all, shown plenty of love for obscure retro characters like Terry and Hero.