I may be completely wrong here, but I understood when Flight was mooted the FS team weren't employed by MS. The ACES team working on FS11 had been 'let go' years before. But I may be wrong...
They were all still around. Closing the Aces studio just meant that the people on the team were deployed to other areas of the business. Many of the familiar names were involved in the development of FS11/Flight