The only way I can see Ridley actually get the representation Sakurai believes he deserves (which includes Ridley at a massive size) is to make Ridley's size his entire gimmick.
The largest characters we've had up until now are Bowser, DK, & DDD. (K. Rool/Ganon would be in this category as well).
The idea now, I believe, is to just make Ridley be a Super Large character, and the only one of his kind. That'll be his entire shtick. He's so massive, all his attacks have great reach and good power, but he's capable of being nailed from that far away due to his own hurtbox. 8-Player Smashes would go one of two ways in a very extreme fashion: he's either winning above everyone because all his attacks are hitting, or he's getting obliterated because everything is hitting him instead.
If they can somehow balance out the gimmick of his size, which I know Sakurai can do if he REALLY put his mind and team to work 120%. He'd have fast attacks with some armor, but each attack would have a slower wind-up with an obvious tell.
I'm not a Ridley advocate, but having a supermassive character might actually be an interesting concept to play with or against. It might completely break the conventions of Smash, but it might be the only way to go even further beyond.
That being said, having 8 Ridley's on screen might be impossible... or it might not. Who knows other than the dev team?