Who knows. Adobe gave Flex to Apache and we all know Flash Builder was really still mostly Flex Builder. I use FlashDevelop for Flash/non-Flex projects. I'm considering transitioning over to IntelliJ for Flex projects.
Apparrently, and correct me if i'm wrong Adobe, but they cancelled Flash Builder 5.0.
That is too bad for them, since that is the main reason i subscribed for CC.
I am very disappointed in how they just dump support for something people already
invested so much time and money in learning and implementing.