I asked my friend Clint at Black Label Armament about this, and he said he feels this ban will lose in court pretty soundly.
My sentiment, too. The big question is: how long will it take for the decision to be handed down? The first time SBT Tactical took the ATF to court for reversing their interpretation in 2015, it was two years before the ATF issued a “clarification” letter that basically re-stated their original 2012 position that braces weren’t in their jurisdiction. Then it was after another six years of legal production and use of braces that the ATF decided, once again, to do a 180 and declare braces to turn a pistol so equipped into an SBR, thereby placing them within their remit. Again.