The brace is what makes it a pistol under the legal definition. If it were a stock the gun would be an NFA firearm. I thought the context was clear, but let me add some for better understanding.
Take a rifle/carbine, shorten the barrel and the stock below the legal limits and you have an SBR, which is NFA regulated. Remove the stock and its a pistol. Put something on the end that looks like a stock but is legally defined as a brace, its a pistol. USE that brace as a stock and brag about it on the interweb will convince people, including those making laws that it is a stock, and they will support the ATF when the ATF gets around to deciding to change the legal status from brace, to stock.
Many of us know about the nuances of the law and how intent plays a part in legal definitions, but many do not. And apparently a number of U-tubers don't know or don't care. And that's a serious PR problem for all of us.
I didn't mean to imply that having a brace makes it a pistol, I meant having a brace, and not a stock, is what allows classification as a pistol where if it had a stock it would not be a pistol, but a rifle (and a short barrel rifle) under the definitions used by the ATF.
Right now all kinds of crap is being thrown at us, and if past experience is a guide, we can avoid the worst of it, but odds are something will stick. And it could just be the govt "re-examining" braces