Those lights at Disneyland come up on risers on the rooftops for night parades and seem to be LED colored lights that change throughout the parade to specific color palettes for the specific float that is passing by. I've noticed that WDW has night lighting for parades too, but they are just general white utility lights that illuminate the street in plain white light.
If they are upgrading the Magic Kingdom Park parade route audio system to be more like Disneyland's, and since Steve Davison seems to design all his parades with onboard audio for night performances, it would make sense that TDO is also installing the colored light system from Disneyland and ditching the old white utility lights. DCA has an identical lighting system installed on rooftops along its parade route too.
But you don't have to use them. For the MSEP they could just keep them in the lowered and off position and do the MSEP as per normal. DCA kind of did that when it was running Pixar Play Parade and MSEP during nighttime based on the season. But at DCA the parade lights would be on and flashing colors prior to the parade, and would then dim and go dark as the parade began at the end of the famous intro.
Here's that intro-lighting example for MSEP from DCA a few years ago, from about the 10 second to 60 second point on this video.
They could do the same type of thing for the MSEP at Magic Kingdom Park, once they got that type of colored light rigs installed on all the rooftops along the parade route for Festival of Fantasy.
