Not to come off as rude or anything, but....
Now we're really opening a can of worms.
For the sake of brevity, a few other patterns (or "facts," if we're making that jump of Grand Canyon proportions):
--"We've never not gotten a fat mustachioed plumber as a newcomer in Smash. We're 100% getting one now too."
--"We've never not gotten a Star Fox newcomer in Smash. We're 100% getting one now too."
--"We've never not gotten two Pokemon newcomers in Smash. We're 100% getting two now too."
--"We've never gotten a character from a new series with just one game. Shulk has no chance at all."
--"We've never gotten a character with more than two guys onstage at once. Chorus Men have no chance at all."
The first pattern can be considered straw grasping rather than a real pattern. Besides, we still have Paper Mario and Jumpman who can very well be playable.
The second pattern doesn't mean much since the only game we got from Star Fox between no and Brawl's release was Star Fox 64 3DS. Melee was only two years after Smash 64, so it's not like Star Fox 64 wasn't still relevant either.
The third pattern is only relevant if you count Pokémon Trainer as one character. As Sakurai states otherwise, there really is not pattern here...unless you are to believe that we will be getting eight characters from the franchise.
The fourth pattern...has Roy having just one game. But if you were implying a one-game series, Xenoblade is actually a part of the same series that brought us Xenogears AND Xenosaga. The only thing new here is the company Monolith Soft currently works for.
The fifth pattern makes no sense at all, however. Especially if you consider each of the Pikmin that accompanies Olimar as separate guys. Besides, it's a new mechanic that we don't even know how it'd work, so....
And as for the Recency vs. Relevancy (what a dreadful word): The problem with K. Rool isn't just that he hasn't appeared in any of the more recent Donkey Kong games. Or that he isn't relevant at all. It's that on top of all that, Nintendo doesn't seem to give a crap about the character to attempt to revive him anytime soon. It's not that we all hate the idea of him being in the game. We're just being rational about his chances (btw, I don't consider Dixie Kong's chances to be any better, even with the recent release of Tropical Freeze; could still happen for DLC, though). It's almost as improbable as asking for classic Donkey Kong to be playable (not the star of DKC, or Cranky Kong), or Donkey Kong Jr.
Now, given the fact that Kremlings are enemies in Smash Run, I'd probably just give him the sixth most likely chance at getting in as a newcomer behind the likes of Chrom, Chorus Kids, Ridley, Mewtwo (technically, a veteran, but I digress), and yes, even Shulk, who is the only one of these characters not to have anything beyond outside sources loosely nodding towards his confirmation, or leaking his status. But here's another way to look at it: The enemies of Smash Run--or at least those not relating to SSE or Namco-Bandai--are directly related to each and every franchise so far to have at least confirmed character representation. The only exception to this are the Sneaky Spirits, and even then, it seems probable at this point that we'll get someone from Rhythm Heaven as a playable character. Ergo, Kremlings are tied to the Donkey Kong series. Guess who's playable? Donkey Kong and Diddy Kong. Not that this disconfirms King K. Rool, but even then, calling the Kremlings a character tease is more straw grasping than it is a hint. But, who knows for sure?