Shulk doesn't even get near the votes of Chrom. After all is said and done, I wonder who will still be left to be voted upon in SSB5. For all we kno, King K Rool, Roy, Krystal, and Junior could be the next Elite Four.
Good question. Excluding the Gematsu's leak characters, these are what I can see happening to the following characters should they not get in this game:
Mewtwo: I'm as close to sure as I can get with this character, but if by some anti-miracle he didn't get in, then it would be dependent on if he remains heavily promoted like he has been lately. If so, he'll probably retain his top spot as most wanted character, but if not, I could see him starting to slide down, with people assuming that a character, once cut, never returns.
Ridley: He's done for, unless Ridley holds multiple roles in a game like R.O.B. did in Brawl; stage hazard for Other M Ridley and a smaller, playable Ridley (which is doubtful at best). Ridley will likely see a serious crash in popularity due to ferocious detractors claiming that "he iz too big!" and supporters being very demoralized by yet another disconfirmation, unless another developers steps up that shows different character philosophy than Sakurai.
King K. Rool: Kremlings appearing in Smash Run is a good sign that Kremlings may be making a comeback. If this happens, K. Rool will end up being the most wanted newcomer for the next game, but if not, his popularity will depress considerably, although less than Ridley. That's assuming of course he doesn't get in this game. I used to think he was done for if he failed to get into 3DS & Wii U, but the signs of Kremlings in Smash Run makes me think he'll still be a contender for SSB6.
Dixie Kong: She's back for good in the Donkey Kong franchise, even if she doesn't appear in SSB 3DS & Wii U. She will definitely be in the Top 5 most wanted this time around, even has a shot for the #1 spot if K. Rool and Mewtwo gets in. Or if she's cut late in development for this game and DLC characters becomes a thing, she could be added back.
Roy: If he gets a remake, he'll probably be among the most wanted characters for the next game. Roy's popularity in Japan is enormous even twelve years after his game. A remake would shoot him up to be among the Top 3 for sure. If not, then he'll be considerably less demanded, though as an extremely popular Melee character, he'll always have a sizable fan base.
Krystal: It's really impressive how she managed to retain a lot of her popularity, even eight years after her last appearance in a Star Fox game. That means that she has left an impact on the Star Fox series and not just an entirely bad one. She'll continue to decline if Star Fox gets no new games, but will still keep a noticeable fan base. However, if Star Fox gets a new game, her popularity will rocket; likely into the Top 3.
Isaac: It's now or never for him and things don't look good. For him to have a chance, fans will have to hope that Sakurai is gracious enough to have nine new series in this game and hope that Sakurai doesn't give it towards a relatively random new series/retro series and that's unlikely to happen. He fails to get in and he'll be hardly requested next time around.
Bowser Junior: He'll continue to make major appearance in Mario games and as people will have expectations of an even larger roster, there will be a movement for a sixth character. Since Toad won't ever get in and people will probably be too demoralized to support Waluigi and to a lesser extent, Paper Mario, people will actually unite behind Bowser Jr.
King K. Rool/Dixie Kong (possibly both if both fail to get in) and Bowser Jr. will probably be in the Top 5 next time around. Everything else is up in the air.