It's pretty easy to see how things would have turned out the other way. If Trump hadn't tarnished the 2A, then Trump wouldn't have tarnished the 2A. Which itself is a good enough reason not to tarnish the 2A.
With that said, it's also extremely unlikely that any gun legislation would have gotten past his veto.
So in reality, if Trump hadn't issued an EO that expanded powers and tarnished the 2A, it's not like "worse laws" would have been passed.