I don't believe they will return to full 2017 HEA if the show returns, it will appear more like Disneyland in Anaheim when old firework shows return. Here's the story behind it at Disneyland.
When Disneyland Forever return in 2019 at earliest amid debut of Mickey's Mix Magic and after the castle refurbishment, they cut most of castle pyro amount just for the Jungle Book segment, as well as many castle pyro cut at Mary Poppins segment, Winnie the Pooh, and finale part of the show while modify some of the original 2015 pyro. The similar situation also goes for Halloween Screams and Believe In Holiday Magic. Even for this year 4th of July Celebrate America fireworks, they no longer showing crossette castle pyro effect at the end of "Celebrate the Freedom and Independence" segment.
Disneyland recently just testing and showing how older fireworks show be looked but without any castle pyro just like Mix Magic, starting with Halloween Screams on October 17 last year, and DLF for three times this month (July 3, 5, and 23). It was apparently same situation at MK when HEA was shown without any castle pyro.