This is not exactly a surprise - AC cut their own earnings months ago. If you look across at the AC board, and do a search, you'll find that their company representative has stated that all fares previously booked as T+ would be re-classified so they remained as T+ rather than drop to T. (I purposefully took a screenshot at the time, just in case it was edited later.)
The re-classification should have happened months ago, but this is AC ...
Probably worth a PM to the lurker to see what's happening if your MMB (like mine) still hasn't been amended.