Some data points to determine the answer. From Aeroplan.com, "you have been a valued Aeroplan Member since July, 1989". From Altitude.AirCanada.com, "Million Mile Candidate 589,123 AQM". Plugging that into Excel tells me I'll reach 1MM on or about May 20, 2039.
Since I've actually been doing ~60,000 AQM/year for the past 5 years, I'd estimate 1MM in 2025.