Gym battle is taking place in the next episode and yes Krokorok is confirmed in the match.
I dunno, I just don't have a feeling he is going to catch it or one for that matter. If a trainer showcases it more then likely it will be Alder. And he could always bring Gible back since BW2 opened the doors for other regional pokemon. And I doubt he will be sticking around Icirrus that long anyways since Homika the new Poison leader is supposed to debut in June.