Not to throw too much cold water on this but,
If implemented, a suit will be filed against it, most probably in Amarillo, TX, with a nationwide injunction going up through the Fifth Circuit, so add a couple of years before it reaches the Supreme Court. Once it gets to the Supreme Court it will have basically no chance of success.
The Supreme Court has recently created the "Major Questions Doctrine." Basically,
Major Questions Doctrine
So basically I would not put any hope in the FTC actually banning "noncompetes."