Scalia did not say all gun regulations were unconstitutional, and that is the loophole through which the libs will try to ban semi-automatic weapons - if Obama keeps his promises that is. He seems to be getting more “pragmatic” about things now that he has won.
Scalia did not say that all bans were unconstitutional, but from his decision (and I haven’t read it for awhile) it would seem that the ban would have to at least pass the rational basis test (which an assault weapon ban can not pass) - or possibly would have to pass the test of there being no rational reason for ownership of the weapon -(this is based on Scalia’s justification for why US v. Miller still stands).