So, it's not at all a "done deal"
Maybe not on paper, but in practice - yes. Very few places try to ban firearms these days, save a handful of large cities known for corruption and crime (Chicago, Washington D.C., New York City, etc.) States are jumping on the bandwagon to relax firearms restrictions and allow concealed carry. The word is out that more firearms in the hands of law abiding citizens lowers crime, it does not increase it.
Laws designed to put onerous restrictions on firearms have been tumbling down for the last few years, without the Supreme Court telling governing entities that they must do this. There are a few cities/states whose leaders are too self-absorbed to understand what's right, so they will have to be told what they must do. It will take a few more years for the courts to "tell" these primadonnas what they must do, but it will come. Aside from the folks that have to live in such places, it is a "done deal" for the great majority of us who live in normal places.