Notice Anything? This week they eliminated the ".Earn up to 15000 miles....." and replaced with the sentence:
Earn Aeroplan Miles on a vehicle purchase or lease (available only in dealer promotional periods – see dealership for details)
The sky is the limit. Each dealer now is free to set the number of miles they want to issue for a car lease/purchase. This is probably in reaction to the Aeroplan 60,000 mile offer at Infiniti dealers.
I think by raising the miles issued threshold, car buying decisions can be positively influenced. That answered my main question.