I'm not really sure it's fair to ask where the classic characters are in Paint the Night. The parade is led with Tinekrbell and a Peter Pan unit, I think I'd consider Little Mermaid and Beauty and the Beast pretty classic at this point, and the finale is a Mickey Mouse unit with several of the classic characters, and songs including
Zip-a-dee-doo-dah and
When I see an Elephant Fly. No classic characters are being eschewed here, and there is no Star Wars and Marvel. They did include Pixar, but Toy Story came out in 1995! It's pretty classic too.
Sure, the new fireworks are themed to Pixar, but they are only for Pixar Fest, at least for the moment.
Disneyland Forever used a lot of classic stuff, and that was only a few years ago. Sure, new characters come in, but the thinking that all the classics are going away just doesn't hold. Over at WDW, the newest ride (about four years old now) at MK is based on Snow White and the Seven Dwarfs!