Yeah I think it would have been interesting if Carpenter had been allowed to follow through on his idea of every subsequent Halloween film being a different, stand alone story.
Definitely, I saw in a documentary that if H3 had been a success, H4 would have been a paranormal story.
In the same vein, though, John Carpenter and Debra Hill actually championed a treatment for Halloween 4: The Return of Michael Myers. It dealt with sort of the longterm effects of what happened in the first two movies. Halloween would have been banned in Haddonfield and in their attempts to suppress the memory of Myers and that night, it would have brought him back. Just on the notion of, if you try to suppress something, it'll only rear its head stronger.
Ultimately, it didn't pan out and Carpenter and Hill sold their interests in the Halloween name shortly afterward.