i do think this is one of the few game ideas where powerloss would make a lot of sense, but at the same time, i would hope that people interested in a game wouldn't need "my characters have no powers" as an excuse to engage with the plot. similarly, i would hope the existence of powerful characters wouldn't inherently ruin the fun of players whose characters do not have powers.

i do think a system flexible enough to allow players to regain their canon powers is a good compromise, though. but then it kind of takes away from the 'classes' thing, unless you had to choose a class that reflects your canon powers in order to reaccess them.