Third hand info, so take it for what it's worth: In the late 2000s, UL Brass made a real push to bring them into the fold. Harold's right hand woman was not impressed. Fast forward to Maggard admin. When they pressed McIlhenny for stadium donations, they didn't get far. The reason exactly? I have no idea.
My wife is close friends with someone very close to decision makers there. I won't get too specific. But we visit with them often. Anytime UL comes up, the conversation stalls or gets awkward. I wouldn't say its an impossibility to fix that relationship, but it would definitely take the right person and some time.