Simple, Flash doesn't allows them. In other words, technical difficulties.
Still, there are exceptions (Fox looks better with his sking changing colors, and Retro Mario, Link, Megaman look pretty good too)
But honestly, the pallette swaps have bugged me too, I think making sprited recolors rather than flash colors would be a better choice.

Enjoy your 5 gig flash game

I think it would drastically increase the time required to load the game. Also, too much work. 5 times the sprites required, for every single character in the game and for every new one that gets made. The current recolors are pretty good imo.

I speculate that if Solid Snake is in 1.0 and single player Adventure mode or a SSE-like mode is still in(post 1.0), Big Boss could appear as a boss battle. He could be piloting a Metal Gear, or fight on foot with a modified moveset based on Snake. Other potential boss battles: Mewtwo(if cut), Galactica Knight, Frieza or another DBZ villain, Magus(Chrono Trigger), Black Knight, Dracula or Alucard, Dr Eggman, Dr Wily, Mother Brain, Giga Bowser,New SSB4 Boss. They could have a Pokemon Champion that uses legendary and Mega-evolved pokemon.

It would be funny to see crazy boss battles like one based on an arcade Donkey Kong level (a bit like 75m)or a Pac-Man level with all the ghosts.

It's unlikely, but we could also see some expansion characters first appear as enemies in Adventure mode

I previously heard about some kind of mode called Flash of Shadows, it's supposed to be like the Subspace Emissary in Brawl. Is this actually a thing?

At the moment, it is no longer "confirmed" as it might of been replaced with something else now.

We are not allowed to know anything even remotely related to that. It's top secret stuff.

i speculate board the platforms

I was playing ssf2 today and was in the stadium section, and I noticed that there are 5 empty slots. In Brawl there are 4 modes, Target Test, Multi-Man Brawl, Boss Battle and Home Run Test. If we assume that all these modes are coming back, then that leaves 2 spaces open; what do you guys think they could be.

Im voting for that Basketball mode Meyguhmein came up with.

I think a stage builder would seal the deal on this game for me, the lack of a Stage Builder in SSB4 for the 3DS was a bit disheartening as I loved it in Brawl. However if it is possible that would be great. Speculatively you could save the stages to files outside of the Flash Game and like when loading previous exported save data it just prompts you to browse for a compatible file to save space in the game. (If any of that works.)

Also race to the finish is a great mode too, and I would enjoy it returning, I loved it a lot.

I could see Stage Builder coming to the game, although I think it would be improved since the one in Brawl was so underwhelmed, it has a lot more potential to be better. And Race to the Finish is a must.

I spec bits for breakfast by cloud will be used in a future target test bc its too good of a beat

I was just playing Kirby Triple Deluxe and I said to myself:
Wouldn't it be great if there was a Kirby Fighters' stage in SSF2?
So, I speculate Kirby Fighters' version of Dedede Stadium.
However, I don't know about the Dedede hazard in case Dedede gets playable, replace him with Alfonzo?
I don't know

i speculate stamina mode. that would not only be loyal to last smash games, but also open up the game for other more "old-school" fighter gamers who prefer hp-based games like Street Fighter instead of a KO one.

of course, this speculation has nothing to do with the fact that i just love that gamemode... yep, nothing at all.

yeah, I would absolutely enjoy stamina mode, nice addition for the special modes

and I hope that they finished that fancy replay munu for the next patch

on the topic of stamina, if we got stamina mode + stage builder we could play a mahvel-esque 2d fighter, that would be pretty hype.