AC says it's generous, and it is still planning to have their own loyalty system. They have to say that. If they say they won't have their own system, and will continue to use aeropeso, ae will know AC really needs them.
OTOH ae just announced the plan for ae 2.0, with redemption rate mostly the same, and even will have charter plans. That must have spooked AC. Meanwhile TD and CIBC know they'll have trouble keeping ae visa card customers as they get closer to 2020. So AC/TD/CIBC feel they can still buy ae on the cheap, and stop the bleeding.
ae can always ask for on Aug. 1, then announce good quarterly results on Aug. 2, then ask for a higher price. The coming few days should be interesting.