I highly, highly doubt it will happen. I can't imagine a case where half the superdelegates are going to switch for the side with the less popular votes. As things currently stand in California,
Clinton has a pretty sizeable lead there (
and in New Jersey, as well), and that really doesnt seem to have favored Bernie all that much. Unless Clinton spontaneously combusts at some point or is abducted by aliens, the superdelegates seem to be pretty firm in their position.
Also, Indiana wasn't really a huge upset. For Bernie to win California enough to impress superdelegates, there has to be a MASSIVE win. Like, I'm talking around 70-30. For Clinton to lose that badly in a state so diverse, she'd have to drop every racial slur and offensive word in the book on a speech and end it by flipping the bird, but otherwise not happening.
It especially doesn't help that some of these superdelegates are getting harassed by Bernie supporters about their positions, further solidifying them as it is. Generally speaking, most (I'd argue a good number) of superdelegates that support Clinton arent a huge fan of Bernie, so it'd take a devastation of abnormal proportions for them to change their mind.