It would seem fair to me that the US ban any recreational user and any owner or part-owner of a recreational-pot business from entering the US for life. I don't see the point in banning medicinal users and legal employees who own no part in the business. That seems unfair and vindictive especially if a person may have no choice but to access that employment to maintain access to any social assistance for example. There is a difference between working for an employer and actually buying a share in a business.
If the US goes through we this, we should reciprocate by banning Trump's casino employees if they do that.