They could build up Wyatt again (LOL) or they could do Lesnar vs Joe II. But, I doubt it'll be happening.
Bálor's yet to be granted a match for the title he never lost in the first place, so why not do it at the Rumble? It's weird on WWE's part, really. He's clearly over with the crowd and they love him despite some of the questionable booking lately, so book the damn match.
Also, I have a feeling it might be Kane who gets to face Lesnar at the Rumble. Meh.