They were never bought by a luxury brand, they were acquired by freedom group with the likes of Remington.
I was never a huge fan of AAC, their mounts suck however the SND6 was a pioneer can for its time, and the first true "multi use can" than could run on 7.62 and 5.56 guns. They also stole the 300BLK and tried to pawn it off as their own.
The best thing that could happen to these companies is get bought by someone like PSA, at the very least, you know they will not be sitting around doing nothing.