I mean... maybe. Assuming that he actually has damning evidence against Kalanick, and that, even presuming that Uber did know about the theft, they weren't circumspect about admitting it.
That seems like a pretty narrow scenario. You have to believe that:
a. Levandowski feels betrayed by Uber (I don't think he has cause to)
b. Uber did in fact know about the theft when they hired Levandowski.
c. Kalanick straightforwardly said something about the theft that was so damning that it makes for a good case a year later, or provided some kind of documentary evidence to Levandowski, rather than wink-wink nudge-nudging.
d. A US Attorney is interested in offering this kind of deal (that is, giving one white-collar criminal a good deal in order to go after... a somewhat richer and more famous white-collar criminal).