I don't see anything wrong with that. The no pay during training and junior bases are well documented on most forums. If you weren't aware of that, the email informs you as such so that you don't waste your or the company's time in coming to an interview if the terms are unacceptable. If the pay and bases are what have you saying" YGTBSM", that's old news. I don't condone the company's practices, but I don't see whats new here either.

Out of curiosity, what were your times when offered the interview?