Flight Sim is said to have been built in an adapted version of the ForzaTech engine and features a very nicely implemented TAA solution, so it’s obviously possible with the engine.
I expect the TAA-aversion when it comes to Forza games is down to the slight softening of the image that comes with it, while one of their goal with Forza is for every minute micro detail on the cars to ‘pop’.
I don’t see why they would feel the same way about an action RPG game, and expect they would go the TAA route.