"Being dangerous to people other than you" is not why refrigerant requires a license to purchase at all.
The license is required because refrigerant is categorized as an ozone-depleting substance, and the sales restriction is established by the Clean Air Act[0]. All of which is under control of Environmental Protection Agency.
I guess you can argue that any pollution-restricting laws are based on the premise of "being dangerous to people other than you," but that's not quite what people have in mind when talking about things being restricted due to being dangerous. We are talking about things like "driving a non-street-legal car" or "owning this one potentially dangerous carpetry tool", not "increasing gas taxes to disincentivise pollution."
The potential danger being inflicted in those cases is direct and specific. You can totally drive a non-street-legal car on your farm, even without a registration and a license plate, as long as you do it purely on your own property and not on the actual road.
And that's the approach that personally makes sense to me with AI-generated images. Any restrictions on it should be imo on the distribution and the commercial/sales side (e.g., you should not legally be able sell ai-generated posters of your neighbor in an embarrassing situation without their permission or sending them to that neighbor's workplace), not on the creation/usage side (e.g., you should be legally able to generate those images of your neigjbor, with any potential restrictions and legal problems only beginning to come your way at the distribution stage).
0. https://www.epa.gov/section608/refrigerant-sales-restriction