Nice speculation........very plausible.
I have no information to back it up at all, but I think it may be likely that reaching an agreement with the Big East in order to extract WVU from the league may have required an agreement that the Big 12 would not pursue any other Big East teams in the future.
If things with UL have "cooled in the last two weeks" we'd be in the time frame immediately following WVU's announced exit from the Big East.
Marinatto knew UL was on the radar, and would be an obvious add in the future, so in the interest of the Big East he would take steps to avoid that defection. I can see Tom Jurich wanting to stay in a basketball focused league instead of being in the deep end of the pool with the rest of the Big 12, despite what many Louisville fans want. And we know Pitino would be on board with returning to the Big East as well.
Just seems to make sense to me, anyway.