I just got out of my political science class and after class I asked my professor about this situation specifically.
He said that since SCOTUS ruled it unconstitutional in that the accused did not effect interstate commerce. The law remains on the books due to it being part of a larger law which would have to be rewritten and go through all the legislative hurtles again.
In order to be charged with 18 USC 922(g) on would have to be interfering with interstate commerce ie: drug possession, some type of business, etc.
Going about your daily business does not interfere with interstate commerce.
In summery you can be charged but unless you are taking part in interstate commerce at the time the charges are unconstitutional.
I really hate the interstate commerce clause lol