Agree that this challenged in court would not have (much of) a chance of being overcome.
But do see opposition (in this case FDA) trying to suggest that products that do not contain nicotine, but plausibly could, are the type that they may seek to regulate under the tobacco act. Thus, they are overplaying their hand, and I believe court cases will challenge that, and possibly lead to motion that the whole act (or at least that which pertains to vaping) is without merit.
I think we all agree that those type of regulations are without merit, even while we can understand how the claims are being made.
But that zero-nic vapers exist does toss a rather huge wrench into the regulation machine that opposition seeks, to maintain full control over vaping.
Going after flavors is another prime example of over playing your hand. Flavors are not a tobacco product.