Probably same question was asked when Planetary Annihilation was planned. Or whatever other 'community project' that is totally, for sure, pinky swear, the Sup Com successor.
I have played the demo, and they haven't even figured out a good UI so far, or even gotten close to what makes FAF good. They're still on their way to even make Sup Com clone that works well, yet alone a successor. And lets not even start on the balance of units, because it's hard to beat years of balance passes.
FAF is not going anywhere, just because someone claims in their marketing for yet to be made game, that 'they're the best!'.