I'm sure this has been discussed to death over the past few days, but I just found out about it now and I'd like to get my thoughts down.
I don't know if this Mii costume is a confirmation that he won't be playable (from a pessimistic side, it seems like the developers are using the Mii costume to acknowledge his popularity while saying that they don't want to make the character; from an optimistic side, they're acknowledging his popularity, and given that Miis can't look or act like K. Rool, there's no possible way that the two could be confused if K. Rool is made into a playable character), but this whole thing frustrates me.
Before Smash Bros. 4 was officially announced, I only wanted a handful of newcomers (aside from all of the Brawl veterans and Mewtwo returning - I see no reason why unique characters should be cut, and while I get that hardware limitations make the Ice Climbers impossible in their usual state, there's no reason why they can't be altered, and there's no reason why so many unique characters should be cut entirely).
-Mega Man - the mascot of a major third party company; his inclusion would also act as a way for Capcom to get some positive publicity after cancelling several Mega Man games and leaving Mega Man out of two different versions of Marvel vs. Capcom 3
-Little Mac - his franchise was recently revived, and seeing as it's based around boxing, it makes sense to include him in a fighting game
-Ridley and K. Rool - Smash Bros. doesn't have much villains to begin with, and both Donkey Kong and Metroid are rather poorly represented.
Obviously, we got Little Mac and Mega Man, but seeing Ridley turned into a stage hazard/pinata after months of ambiguity was incredibly annoying; Sakurai using "he's too big" as part of his excuse for excluding him just made it worse, given that plenty of fan efforts seemed to indicate that getting him to a reasonable size was doable. The sheer number of cuts from Brawl, and some rather questionable character choices (Wii Fit Trainer and, even if he barely took any effort, Dark Pit) didn't help.
Aside from Snake, the main character that I was hoping to get from this DLC was K. Rool. It made sense - even in the final game, Donkey Kong was represented quite poorly as a whole, which really stood out given that it had several major releases since Brawl. K. Rool's been demonstrated to be pretty popular worldwide, even in Japan, so it seems unlikely that he'd be left out of the running like this.
I'm hoping that K. Rool is still planned for DLC and the development team didn't realize the impact that something like this would have, but I thought the same thing about Ridley (figuring there's no way the team would be so tone-deaf as to take one of the most wanted characters and turn them into a stage hazard) and I was wrong there. I want to be optimistic about all of this, but I just don't know (then again, I haven't had time to read the last twenty or so pages; if there's anything on there that might give me some hope, I'd like to know).