Even though they should have had Bryan join the Wyatts a month or two ago if they were contemplating this scenario, it makes a ton of sense for Bryan to betray Wyatt to win the Rumble. That way, they have something for Bryan to do at Elimination Chamber before he comes into the WWE World Championship storyline again. It gives the perfect amount of time to bring closure to the Wyatt storyline. So you're pretty spot-on with that.
But again, I feel that having Bryan betray the Wyatt Family at the Rumble is way too quick a turnaround on the storyline, so I don't really see WWE doing that. I'd love it if it happened, but I'm not going to hold my breath.