To go back to the examples of Jekyll/Hyde and Banner/Hulk, those seem like good candidates for a Humanoid version of Beast Change. However, one should take into account that both of their alternate forms had serious social disadvantages.
Hyde "put off" everyone who ever met him, though he generally chose to associate with lowlifes and rabble. And the Hulk? Giant green monster.
So, yes, both of them could qualify for a Skill Shuffle as well as a set of Inhuman Powers linked to an Human Form with an additional discount for how Uncontrollable it seemed to be for each of them.
But these are from other fictions: one, an analysis of the nature of evil using a character with an expiration date; the other, an ongoing comic book.
1. I really hate it when people use the novels in this sort of discussion. Just a pet peeve of mine.
I greatly prefer to reality-check things like this against the extant fiction. In some places it can bog things down, but it is still something one should not discount.
The rules may not explicitly say Humans are off the table as an option for Beast Change, but it is pretty easy to infer that, and from my point of view, pretty hard to infer the opposite, and I do not believe "Beast" automatically or even rhetorically includes humans.