On the topic of the fandom and how it shifts moving forward, I think it's time for a shake up. I've loved a lot of traditionally popular characters because I very much grew up with so many of them. King K. Rool, Banjo Kazooie, and Geno were all characters I'd encountered and loved prior to ever considering them as characters in Smash (here's hoping the most unlikely outcome of Geno finally happens, but I know it's a long shot). I think we'll see people like me going forward who still end up with attachments to these characters and join in with any of the old guard who are still pushing for certain characters. I don't think you'll ever really see certain characters go away at this point, though I do think we may begin to see more and more dropoff.
And honestly, it makes a lot of sense. Most of the characters that were desired in the Brawl era have now either made it in or have dropped off completely. Geno, Isaac, and Bomberman seem to be really the major ones left at this point. Smash 4 has more requested characters left, but most of the top have made it in already with like Bandanna Dee being left over. The list of big requests the community can rally behind has shrunk so much with Ultimate's release. I think a lot of people are just plainly satisfied right now and are ready to move on from speculation.
Which is a really good thing for the community since it opens up all kinds of new possibilities for speculation and lets some new blood take over the reigns. More than ever, this last year seems to have been a frustrating experience for a lot of newcomers who want non-traditional picks for the Smash community. Seniority doesn't really mean much and really shouldn't. You're requesting characters in a video game, not building a resume for a career. There's nothing inherently more deserving of your 10 years of support for one character to someone's 6 months of another. All this speculation and discussion is just supposed to be for fun and because we like talking about the games, but I think people have gotten way too invested to the point where it makes the community standoffish and often exclusionary. Again, I love and want Geno, but I don't really give a damn about how long he has been requested in the Smash bubble. That doesn't make him a better character choice than someone like Steve on principle.
I mostly want to see a community that doesn't freak the **** out every time things don't go their way or when choices not specifically tailored to them show up. Street Fighter, Final Fantasy, and Dragon Quest are massive franchises with huge appeal to a wide variety of people, but you'd think they were niche games based upon how some people talk and react to their inclusion in Smash. Smash has moved beyond just being a Nintendo character focused fighting game, and we need to accept that it has become something much bigger and arguably better. With that change, a whole new field of possibilities has opened up to genuinely excite people in way that Mach Rider for example never will be able to (nothing against Mach Rider, but a great example for what I'm talking about). And beyond that, so much of the creative stuff in Smash has come from places other than the most requested fighters, and I hate how they're constantly derided despite their uniqueness (R.O.B., Wii Fit Trainer, Piranha Plant, etc).
I know much of the community has gotten better than it used to be, and I know I'm strawmanning a little bit here since I'm addressing a lot of things at once, but I do want to see the community finally break the deadlock of traditionally popular character choices and look forward to such a future.