If the argument is that the Big East is going to be down this particular season and that will depress interest, then I agree with you. However, it's a little bit of wishful thinking that brands like Georgetown, Villanova and St. John's are going to suddenly disappear and will be deemed to be midmajors long-term. I've seen a lot of snarky remarks about Creighton on this thread, yet they've been selling out 17,000 seats per game with a Missouri Valley Conference schedule. You can count 5 schools in America that have better attendance than Creighton: Kentucky, Louisville, Syracuse, UNC and Indiana. Once again, that's with a Missouri Valley Conference schedule (and, to boot, it's in the most college football-focused market that you could possibly get: the state of Nebraska). Marquette also sells over 16,000 seats per game and is in the top 10 of basketball attendance every year. Can anyone in the AAC (including UConn) say the same? Heck, the vast majority of schools in the Big Ten and ACC can't say the same. Plus, the Big East is still going to be playing its conference tournament at Madison Square Garden. It's still going to have tradition-rich schools that are located directly in several of the nation's top TV markets and recruiting areas.
So, let's not overstate things. While the New Big East is in no way, shape or form as good as the Old Big East for basketball, the new league also isn't within the vicinity of being a midmajor. There are going to be years where the AAC may be better than the Big East, and I'm sure there will be years where the Big East will be better than the AAC. Neither of them are midmajors (just as I don't consider the MWC to be a midmajor).