...and with any luck so will Microsoft.

That's always the easiest way...Cheap and easy.

From what I have seen MS Flight's FM compared to the FSX stock planes is in many aspects even better, you feel more and it's way less on rails.
Full clickable cockpit and procedures list to help you with every aspect of flight.
Weather has more effect on the planes at least with the Boeing stearman.

Overall at least during free flight MS flight is a copy of FSX with better optimized graphics engine (better performance) and improved FM.

No Traffic controller or AI planes I don't see why not in the final version.
Also one thing is clear. We need bigger maps...

All the videos you have seen previously were in easy settings like you could see on FSX too. Totally misleading compared when flown full realism settings.