Smash is a celebration of Japanese video games. You're primarily gonna be getting characters that meet their cultural tastes and you're almost always going to get their main character. You can always do custom Mii Fighters tbh, even if that's a cop-out answer. Elma was a character a lot were hoping to see, but unfortunately, her game wasn't too popular and even then someone would probably argue that she's actually an alien and doesn't count. Little Mac's coach is seen in there sometimes, and Twintelle might get in based on pure popularity within ARMS should they get a rep. I'm not sure about alt costumes for Squid-kids, but one of them might be dark skinned like the girl on 2's cover. Which would make sense given how the squids there can be customized.