When the news of Super Sons being cancelled broke, Tomasi ,besides stating he wasn't done yet with the boys, also said that there are "plans afoot that he can't share at this early juncture but you will be happy with the result- Super Sons lives"
https://twitter.com/PeterJTomasi/sta...46942525952000
While his use of "yer" instead of your in the subsequent tweets and the use of Daffy and Bug's picture seemed to hint at something Hannah-Barbara related, I don' t think he was only talking about the Blue Falcon/Dyno-Mutt special. When Tomasi mentioned the special a couple of days later, he called it "a little surprise to ease the temporary pain". The emphasis is mine.
https://twitter.com/PeterJTomasi/sta...98512523169793
So, my guess is that DC perhaps hit the pause button on both Supergirl and Super Sons and will either relaunch or put them on new teams after Man of Steel concludes.