Considering how much it's been requested, if it's just to get Trials / Tutorial for all characters, that's really enough. Like throw in a master character like KI2, and have him reveal bits of character story and stuff as you train in moves, combos, and have character nuances explained to you.
Blech. l'll be really upset if they didn't make stages for new characters in order to make dojos and in-game training for other characters like this. That's a complete waste of MS/IG's resources for content most people will use once and never again, never touch at all, or never work as well as having a real person explain such concepts. There are tons of training videos and tutorials online that will either better summarize and/or easily surpass the depth you can program into an in-game mode, but only MS/IG can make new stages.
These comprehensive tutorials that people keep requesting are easier said than done, and sound great on paper, but I don't think people grasp just how hard it would be to actually make such a thing. That would be a terrible trade-off, imo.