Isaac wouldn't come to BYU to be QB2 under Jake when he could remain QB2 under Rising, if Cam really did come back to give it yet another go next year. Jake will be without question QB1 going into next fall if BYU continues winning as they are this year and he keeps improving himself incrementally as the rest of this season goes on. If Isaac were to transfer, it'd most likely be to a program that would be in search of a new QB1 after losing theirs to graduation, draft, or TP and not having anyone left in their cupboard to be excited about.
But I guess there'd still be the excitement of seeing Utah's QB situation continue to unravel and the thought of other good QBs out there not wanting to step into that mess.