Of course they aren't going to make significant appearances in Smash, that's a given.
Whether or not Ridley is ever a playable character, I really don't care, but it will never change the fact that it's hell-a-stupid for Ridley to be made mini when a significant aspect of his character is the fact he's an enormous imposing alien monster. Yeah that enormity may fluctuate from game to game, but it's still enormous.
I disagree. Size is a part of the character for Kraid, but not Ridley. If size was a factor for Ridley, he wouldn't be hunched over all the time and would be stood up in order to make himself taller, and alongside that he wouldn't change size so much in games. In Super Metroid he wasn't very much bigger than Samus. Plus, even if size
is important to the character enough where he has to be very big, he can literally just do what he always does anyway and hunch over forwards with his wings in the foreground and background.
Other than that, regarding the Hunters... I think they have about as much chance as the Other M squad. Sylux might have potential, but only for the next game, because as of now he's not solidly in any game but Hunters. If another "Hunter"-esque character was going to get in, it would have been Dark Samus. Without Dark Samus, it's Ridley or bust for Metroid. The next Hunter I see in-line is Rundas due to popularity, and even he has no chance of being considered above Dark Samus because he's a oneshot, like pretty much everyone else.
I agree with the sentiment that Metroid could have some other really good characters (humanoid, too) eventually, but after what Other M was, I'd say they likely need to go back to Samus traversing alien worlds alone against Space Pirates for a bit. Other than that, I'd be totally fine with more recurring characters. Maybe even Anthony, but... I'd like to see him get a bit more independence with his character design if they do. A regular GF uniform isn't very enthralling.