Stages, given the time and cost, really don’t seem realistic at all. Same goes for ultimates, and I feel like Adam has outlined why they’re an issue in particular. I get people wanting both of these things, but at least for ultimates, I tend to think / hope that these will be a high priority for season 4, assuming that season happens.
Honestly, if this is something that they can devote time and resources to, I don’t think that people would be angry at all. There have been tons of posts from people not only wanting Mira, Eyedol, Raam and Rash to get their own backgrounds, but retro arenas, the sky stage, etc as well. If they released a stage pack in the interim between season’s 3 and 4, I think most people would love that.
Sure, you’ll have some malcontents complaining about not getting Mira or Eyedol’s stages as part of season 3 and having to pay for them, but we already know what the trade off is for that and it’s up to each person to decide for themselves if that was worth it.
At the end of the day though, that’s the direction they decided to go so at this point, any stages not tied directly to what they plan on doing for the next season would have to be considered extra content. Even if some don’t see it that way, I’d be shocked if they weren’t a cranky minority that gets drowned out be a vocal majority that were over the moon with the idea of getting more stages and gladly shelling out for them.
But yeah, as a community fund idea? No. Simply not feasible and wanting something badly enough doesn’t make it any more possible.
I’m thinking stuff like the following would be good:
-Real Boy Omen (ie give him all the accessories, colors and retros that a normal character has, maybe even reskin him so that he has a bit more of a form to him, with clothes, etc).
-Reimagined Character: I’d have to think that they asked about this idea for a specific reason and I’m assuming that it’s for either a bridge character while we wait for Shadow Lords or as a community fund character. My vote is still for Ben Ferris. 
Wouldn’t mind Shadow Orchid or perhaps Kelvin (provided he gets a new name lol).
-Additional Accessories or theme packs: I don’t think they can do this for EVERY character, but maybe a pack or two with a new accessory set for six characters?
-Variation on existing mode or low issue new mode: Maybe adding more stuff to dojo mode and updating that or putting some new ideas in to survival mode and giving that a new name in addition to regular survival mode or adding a time attack mode or something that wouldn’t require an insane amount of new resources?
