I think TN staying east depends on which line they end up on. If they are a #2, they are the lowest ranked #2 at this point and end up getting the worst 'preferred' location. If they end up as a #3 seed, they have a chance to be the highest #3 and would get a more preferential location.
On UNC - yes, they could end up dropping out of the NCAA if they don't get their s__t together.
As for seedings and locations - not sure Charlie was all that accurate ever, but in terms of teams making it into the NCAA or not, with the exception of the ones that get in just because of a win in their conference championship - he does a really good job.