Dreamlights is itself a partial "remake" of MSEP so to speak, so the precedence of creating new parades heavily inspired by older ones already exists.
Dreamlights is brought up in discussion because it stands as a fantastic example of Disney creating something that brilliantly blends nostalgia AND originality. They maintained the original msep soundtrack with some newly arranged bits as the parade progresses. And the floats are a great mixture of both brand new ones as well as heavily upgraded versions of some of the msep originals (brought up to modern lighting technology standards).
So the idea is not to simply rebuild Spectromagic exactly as it was. Rather to create a new parade heavily inspired by Spectromagic. Bring back the original soundtrack with newly arranged parts where appropriate. New floats mixed in with heavily upgraded versions of older Spectro floats (using new lighting tech). Thus a "Dreamlights equivalent" of Spectromagic, satisfying both nostalgia AND originality.