Mirage sales are down significantly. (This yr.)
Pickup truck sales continue to dominate.
If I had to bet, I'd say there won't be a 7th gen Mirage coming to North America. We'll get a refreshed fascia (2nd refresh, 3rd "face") on the car for the 2021 model year, at which point the platform will be in its 9th year. Mitsu may stretch it to 10 years of production as they did with the Lancer.
So if the last Mirage is sold in Canada in 2021 or 2022, that means I can reasonably expect to still find decent used ones for sale in the 2030-2035 timeframe.