Yes, it is. It would harm UT for the SEC to be considered the equivalent of everyone else, unless we were to reach Clemson heights. The SEC is THE brand of college football and it is for a number of reasons, but the main two that go hand in hand: winning % against everyone else and the number of NFL draft picks. Why do you think kids from the West Coast are even considering Tennessee and other SEC schools in the numbers they are now and ignoring most PAC 12/14/whatever schools including USC? It is because the Vols come calling with "Here is your opportunity to be considered the best of the best, play in front of huge crowds and on TV during the day, not after everyone in the East has gone to bed and best chance for a big NFL paycheck."
The SEC and B1G understand branding. The other P5 conferences do to of course, but the ACC and Big12 share or are too close in much of their footprint to the SEC. Of course, if it were Tennessee and the 13 midgets in a reversal with the ACC, UT might be okay, but Dabo has built something special which no other school has been able to do outside the SEC. Excluding Clemson, no one but OSU has come even close in the last ten years. When UT rises to the one of the top SEC teams, that will mean more. If not, then he!!, let's jump ship and go the Notre Dame route, but we're not Notre Dame with 60+ million Catholics pulling for us nationally.
Some of that kind of rambled, but the gist of it is we need the SEC and the SEC needs us. To be great again. Go Vols.