AE was left to fall mid last year. They were in survival mode. People worried and some said to burn the points asap, in case ae dies early.
But ae's quarterly results kept saying there was no run on redemption. Partly it was because many people couldn't get seats, but mostly because many people thought there's still lots of time. Anyway, redemptions didn't skyrocket.
AC still thought they crashed ae, and of course always considered buying ae back on the cheap.
Meanwhile ae contacted many airlines and alliances. They obviously got some assurances, then announced ae 2.0, especially confirming same redemption points for most flights, for nearly 20 airlines, and also hotels/cars/toasters. AC goes holy sht, ae is not dying but will be healthy, and ae database is very valuable and can even fall into competitors' hands. AC is also probably behind in building their own system. TD and CIBC is not necessarily as worried, as they are likely partners with AC in 2020 anyway, but would still find it beneficial to not lose ae customers, but more importantly to thwart ae partnering with other banks. So AC in panic mode, launched the hostile takeover. AC gave the Aug. 2 date, before ae's quarterly report which probably will be good, and rosy forecast.
Now there is confirmation ae is talking to Oneworld. Ae must also be talking to others. Ae suddently has a much stronger hand, and probably will ask for a much higher price from AC, or just show middle finger to AC and firm up partnership with AC's competitors.