This won't come back. They can try but the pistol brace ban was opposed by nearly everyone and nobody complied. The writing's on the wall, this was DOA.
In general, firearm ownership and usage has been on the increase so their traditional MO of attacking gun rights via legislation and arbitrary ATF rules hasn't been working and they know it.
I think they're going to just change tactics entirely and go with financial warfare. Our ammo all comes from just a small handful of places so they can put the squeeze on these few ammo sources to drive up the prices to where we literally can't afford to exercise 2A anymore. That and taxation.