I feel like Disney wouldn't make an entirely new parade, but just take MSEP and update it with newer floats.
They already did that, with Anaheim's pocketbook, no less. The Electrical Parade was refurbished, majorly upgraded with LED lighting, and new floats were added in 2009 for its run during Disneyland Resort's first
Summer Nightastic promotion.
Summer Nightastic was a summer promotion for Disneyland based on the all new upgrades for Fantasmic! (the new animatronic dragon was the headliner), with lesser upgrades to the Electrical Parade. Plus a new fireworks show and assorted dance parties and décor. It also got a catchy commercial jingle that blanketed the airwaves in Southern California in the summer of '09.
The jingle played up the ability to easily park-hop on those gorgeous starry summer nights that Southern California is famous for.
Summer Nightastic! was a hit in '09, and was copied by Walt Disney World in 2010. When Disney California Adventure began major park-wide construction work in 2010 for its $1.2 Billion makeover, the DCA parade route had to be closed and all DCA parades were put on hiatus for two years. The Electrical Parade, in its 2009 Summer Nightastic format, was shipped to WDW in the spring of 2010. The parade has been in Florida ever since.
I imagine because it got a major refurbishment and tech upgrade, plus a new Tinkerbell float, in 2009 at Disneyland, the Electrical Parade can be used by WDW through at least the end of this decade. If not into the 2020's.
A new night parade debuts at Disneyland in May; Paint The Night. If it's a huge hit, I could see WDW's Magic Kingdom Park getting a version of it later this decade.