States already have the prerogative to reform insurance. Federal law provides that states are, primarily, responsible for doing so.
Only, secondarily, when Congress provides explicit federal legislation, will the states not have primary regulatory authority.
The problem, supposedly, comes in when the employer is located in more than one state, and does not self insure.
From the insurer’s standpoint, this should not be a large obstacle, if they are already licensed in the states the employer is in.

If the employer is large enough, he self insures, so he is not subject to state regulation.
The bigger problem is when small employers wish to self insure, say through a multiple employer VEBA.
Here, many states have chosen to license these entities as if they were commercial insurers.
Of course, federal law provides that a VEBA is a non commercial insurer, in that its products are not available to the public.
In addition, part of the reason for its tax exempt status is to offer plans not commercially available.
It is ironic that states were given the ERISA exemptions they desired in this area back in 1983. How much good came from it?
Don Levit