The Big 12 has to get it's own house in order first. We will know in a year or two if Texas can keep the conference together or not.
The most immediate and somewhat plausible scenario where UCF can be a winner is if the Big 12 "disintegrates" rather than renew the GOR "as is" in a few years and the AAC can absorb enough of the leftovers to "elevate" the conference. Then it's a matter of perception and whether or not the remaining P5 conferences and bowl partners see a benefit. Of course that all depends on what Texas and/or Oklahoma (and to some extent WVU) want to do and whether there is enough TV money there to continue that arrangement.
First, I really don't think the B12 is going anywhere. They make good money and Texas is happy running the show. If the Longhorn Network goes away, then they may start looking, it it could eventually morph into a B12 network. Who probably isn't that happy? OU, but they've no place to go currently, and they've got an OSU problem.
If the B12 disintegrates, meaning Texas
and Oklahoma end up in other conferences, then the B12 will likely be heading the way of the Big East. It would be every school for itself. Likely Texas and OU would likely be taking other schools with them to a new conference, so the B12 would like have, at most, only 6 or 7 schools left. It will be difficult to retain true power conference status, over the long term, with some combination of these left overs: Iowa State, Kansas State, Kansas, TCU, Texas Tech, Baylor, OSU, and WVU. This was true for the Big East post the 2003 raid. It cobbled together enough to maintain BCS membership, but the separation between it and the other BCS conferences was beginning to widen and the writing was on the wall (not unimportantly, it didn't have a major bowl tie in that would have left it out of the New Years Day 6/CFP organization). The fear of that scenario is likely why the B12 was looking at expansion in the first place. These non-UT/OU schools want to boost their numbers so they don't have as arduous a time rebuilding if something catastrophic happens, like OU or UT leaving. Regardless, if something were to happen, likely the B12 remnants would be picking schools out of the American, not the other way around. One or both of UCF or USF probably gets taken, absolutely. If I had to guess in a scenario where the B12 loses UT and OU and at least one other, the B12 backfills with more than 3, probably 5 or 7 to get to 12 or 14: UCF, USF, Cincy, Houston, ECU, Memphis, UConn, or SMU, depending on who leaves with the other schools and if anyone else finds a life raft. They then try to make a case to be a Power 5 conference, but my guess they'll face the same problem as the post-2003 Big East and eventually fizzle into the best of the G5. Major bowls just aren't going to want to pair with that group and it will have a hard time getting a CFP slot and equivalent network deals to what they have now.
No matter, what WVU wants to do couldn't be more irrelevant. They would definitely like to be in the ACC though, and I think Pitt would like to have them there. The rest of the conference, not so much.