Hi everyone it's Xebs, SQUARE-ENIX has previously said they plan on creating more Theatrhythm games using their other franchises, and they're doing just that. Theatrhythm Dragon Quest will be released on March 26th in Japan. SQUARE-ENIX will debut the game at the Jump Festa 2015 event from December 20th to 21st, where they will also share the game's first trailer. You can visit the game's website by clicking here.
I do hope SQUARE-ENIX will make a Kingdom Hearts Theatrhythm game, someday, figures crossed.