Shovel Knight almost definitely would be pre-ballot if he got in, IMO. If there is a limited number of development time for ballot characters, why on earth would you throw a big chunk away on a character guaranteed to sell less, if at all, in one region than characters that are demonstratively popular in all regions? This is not the main game, this is a time where characters have to sell on their own, so that would be a horrible money-making move if your alternative is getting someone like K. Rool or Inkling in the mix.
On the other hand, if it's some behind-the-scenes business thing independent of the ballot, like some "reward" for Yacht Club's work or whatever, Shovel Knight makes a lot more sense. Heck, I still think there may have been reasons like that behind Ryu's inclusion with Capcom, even though you see people trying to say "heh heh he placed like 30th on a fan poll but was added anyway therefore all your fan polls are wrong and K. Rool is overrated/not as popular as [insert character here]."
The implications where K. Rool is involved are that, if everything before Sept. 30 is pre-ballot, we're quite possibly off the hook where the costume is concerned. It being a lone "consolation prize" makes little sense if everything else was pre-planned.