One of the big uncharted zones of First Amendment law (here there be monsters) is professional-client speech. Courts have generally assumed that some restrictions on such speech are permissible:
Hines v. Alldredge (5th Cir. 2015), on the other hand, basically held that such speech can be freely restricted. (The law there “require[d] veterinarians to conduct a physical examination of an animal or its premises before they can practice veterinary medicine with respect to that animal,” including when the practice of medicine was simply giving advice to the client about what the animal needs.) Lower courts dealing with laws restricting psychotherapy aimed at “straightening out” gay patients through speech have disagreed on which legal standard to apply.
The Supreme Court will shortly consider the petition for certiorari in that case, and might — for the first time — give lower courts some concrete guidance on the matter. Worth watching to see what the court does with it next week.