Such a "ban" would be meaningless and unenforceable. You could ignore it with impunity. It'll never happen. Just a source stirring a pot for attention.
Yep, I'm sure many said the same thing about quite a few of the laws on the books today.
Also... It wouldn't be a "ban". There is no "ban" on machine guns or suppressors or other NFA items. You can still own them, provided you pay the 200.00 tax stamp and jump through all the hoops. If you are lucky it will only be about a month to "approve" the purchase of that NFA semi-auto you took a hankering too! Most likely it will be 6 months, but hey, it's not like you "need" it right now. All perfectly "Constitutional" as the USSC says.