The most recent show Disney Live Entertainment produced was the Holidays in Hollywood show for Jollywood Nights next door at the Theater of the Stars.
When it first debuted it was at 27 mins. The following year they cleaned things up and cut out fluff bringing the time down to 25 mins, which did make the show flow smoother & overall better.
I'd imagine the new Villians show would be around that of 25 mins, especially since there's probably gonna be 5-6 showings per day with the equity cast. It's also probably gonna stack on top of the existing BATB and Indiana Jones shows.
Currently the first show of the day for both start at the same time, but then after that IJ starts 15-30 mins after a BATB show starts. Add Villians to that mix and they will all stack and rotate to help ease and pull guests.