Hopefully, he'll get a significant redesign in the process. A concrete personality and revised appearance that moves away from the 'discount Bowser' aesthetic would help a lot. As it is now, though, I'd much rather see Dixie or Cranky as newcomers.
I absolutely agree. DK, Diddy, Dixie, Cranky, everyone else that's been in recent stuff has been redesigned from the Rare days and they're better off for it. K. Rool has had some minor design changes but he could really use a full-on redesign like the others.
I think the big difference between Bowser and K. Rool is basically just that Bowser is a successful king with a princess kidnapping problem, while K. Rool is a spiteful dick that just wants to mess with the Kongs. Bowser kidnaps Peach because he either wants to rule the Mushroom Kingdom or has a crush on her, depending on the game. K. Rool steals DK's banana horde for the hell of it, kidnaps DK and demands a ransom of bananas(why), builds a robot to kidnap DK and Diddy for seemingly no reason, and then he builds a giant laser to blow up DK's home. Because ???
He just hates the Kongs and is an asshole. Bowser's got goals and ambitions, he makes power plays and tries to do stuff without it all being about Mario. K. Rool just wants to humiliate and/or defeat the Kongs (and may or may not want their bananas?). They could probably push that angle and make it work. He doesn't have to be a complicated guy. Plus his penchant for costumes is something Bowser certainly doesn't have.