We know for sure that there will be more episodes. Ian and Toby were filming a special end credits sequence not too long ago, Kali Ciesemier was promoted to art director, and Geneva Hodgson to supervising director.
But nobody knows if Season 3 will be the last or not. I personally think it might be, what with the closing of the P.O.I.N.T. plotline, as well as all these new CN shows that are getting greenlit and renewed for second seasons: >Apple & Onion >Craig of the Creek >Summer Camp Island >Victor and Valentino >Infinity Train >Mao Mao: Heroes of Pure Heart >Tig n' Seek
That’s a lot of fucking new shows. Add the countless number of OK K.O.! Krew members who’ve moved onto other projects (Danny Ducker just recently announced that she’s working on Battle Kitty now) as well as pic related, and it’s starting to look like the end draws near.
If it is, I really fucking hope the OK K.O.! Krew got to end the show on their own terms rather than getting cancelled by Cartoon Network. If Ian and Toby wanted to end it with three seasons, that's fine by me.