What I find funny is if Rose comes up short against Joanna
then she can put the shoe on the other foot and use her
championship rematch clause and we'll be at it again for the
third time.
Rematch clauses are for the WWE. No one gets a guaranteed rematch for their next fight but if the UFC/WME wants the person to fight for the belt, they will fight for the belt.
That being said, I absolutely agree with you that it would happen again. And the UFC has little incentive not to make the rubber match should Joanna win. At that point, you'd have an established feud that would garner interest. Additionally, if Andrade beats Tecia (and I'm rooting for Tecia but let's face it, that is stylistically a very problematic fight), then it makes total sense to have Rose vs. JJ III should Joanna reclaim the belt.
Tecia would be out of contention. Cynthia is out because she lost to Esparza. Esparza lost in vicious fashion to JJ (and probably has a little more work to do before getting in there in a rematch), and Andrade lost in lopsided fashion to Joanna.
So that basically leaves Herrig who has her hands full with KK.
But yeah you would be in a situation where the rubber match would be the most logical fight.
Now, if ROse wins again, Tecia/Andrade is the obvious next contender. If KK beats Herrig, she is on the docket too should Rose continue to hold the belt purely because she is high level and the last to beat the champ.