if she was as popularly requested as people say she was, she'd have a mii costume like Geno and King K Rool. Just saying.
I think the thing that should be addressed was that Starfox's Smash 4 treatment was Orbital Gate, which took a whole damn year to make, It stands to reason that after that they felt like Star Fox got enough attention, especially since the series was on hiatus it hardly deserved a newcomer, and Wolf was a very last minute clone that, hard to believe now, had pretty poor initial reception. So rather than waste time on giving them anything else they simply didn't get him any attention, I mean Wolf scored only a bit under Lucas in Japan's popularity poll, and we didn't even get a Wolf outfit either, being a mii costume only means they have some kind of popularity, I mean hell after that we got a Black Knight mii costume, the Black Knight is certainly not very requested. In fact sakurai has come out and said that Mii Fighters were added because of the concept that anyone can join the fight as them because there are characters that they can't add, and while we did get the inklings, that's not necessarily something that's a guaranteed benefit, it may mean they couldn't get their hands on the character, I mean Sakurai came out and tried for Geno but it didn't work out, so we only got the Mii Gunner outfit, her popularity really only suffered in 2016, after her fanbase **** themselves over Zero, which hardly matters for her official perceived popularity because the roster was likely being constructed soon after the ballot ended, where Krystal's popularity was still strong as it had been. Again she's no Ridley, but to neglect her popularity because of the recent drought is largely irrelevant to her place as a desired smash newcomer. Her not getting a Mii fighter outfit can be due to a several different reasons, In fact if she got one, I'd be far more concerned of her inclusion chances. I await my judgment based on SF grand prix on how nintendo feels about her, I stand fairly confident that she'll be in it, this will give her a good fighting chance for this smash's DLC cycle because It's hard for me to believe that Sakurai had any information on Grand Prix existence, which could mean, and probably does mean no Krystal in the base roster, though the chance still remains.