Folks, we need to accept reality for what it is and not what we want it to be. The folks in charge at Microsoft today could not possible care less about the PC flight simulator market. The only reason the FS series became the multi-generational title it became is because the number two man, and co-founder, at Microsoft for so long, Paul Allen, was a devoted champion of aviation, general aviation in particular. Allen demanded that the FS series continue and what Paul wanted Paul got! When Paul Allen retired in 2000, that champion left, and the only surprise really is why it took until 2009 for Microsoft to fire the entire Aces Studios staff.
Even if there was lingering interest (and trust me there isn't any) the truth is Microsoft is facing serious challenges in far more vital business areas. Due to their refusal to support anything past IE 8 in Windows XP (which remains the most prevalent O/S in use today), for the first time ever IE lost its rank as the number one internet search engine, overtaken by Google Chrome.
Microsoft is also losing big on their O/S future as people are increasingly unhappy with their products for tablets and PC's.
The only serious option I see to reignite a PC based flight simulator is for people to convince Paul Allen to finance such a project with another company. The only way I see that happening is to write the code with the intention of supporting commercial uses and expand the market to include anyone who wanted to purchase it for any reason, including good old fashioned entertainment. In that respect, perhaps the best course would be to try to enlist the help of Paul Allen to convince Microsoft to unshackle their current limits on ESP derivatives such as Prepar3D.
I give none of that much chance.
Ken