A couple of thoughts:
(a) Notre Dame turning down the Big 10 a few years ago was not good, long-term judgment. The reasons are understandable, but their self vision of tradition, lofty independence, and preference for non-shared revenue, gets overstated and its value has limits. The past will not necessarily determine the future. Army had glory days too! The University of Chicago was once a Big 10 member.
(b) It needs to be noted the BE, when they did retrieve C-USA replacements, turned down Memphis. There is a reason: The school, geographically, is far away from most of the BE. Actually, their former conference brethern, L'ville and Cincy, are not particularly hunched up to them either. A bb case could be made for UAB almost as much as Memphis. Memphis actually has an ideal location as C-USA is currently structured. If far away East Carolina left, it would not be a problem for Memphis. Memphis natural rivals include Southern Miss, UAB, Tulane, and maybe Houston. They are close to OOC schools such as Ole Miss, MSU, Ark. State, and Vandy. Memphis is a deep south, gulf region, gateway to the southwest school. It is the southern Mississippi River, not the Ohio River, midwest, and certainly not the northeast. Unless the BE goes to 12 fb, and adds two or three more to its southern flank, Memphis is less than a logical choice. East Carolina, and perhaps Marshall, on the other hand, make more sense. While Tommy West has got Memphis with a winning record, and they are home to the Liberty Bowl, Memphis does not have a sustained winning fb tradition, nor do they have an enthusiatic and major following, compared to some other regional campuses. If C-USA looks like a stretch from ElPaso to Greenville, North Carolina, the BE may want to be careful and not look too much the same.