This would likely depend on the terms of the contract with the drivers and on what statements if any were made to drivers about how rides were allocated, priori

This would likely depend on the terms of the contract with the drivers and on what statements if any were made to drivers about how rides were allocated, prioritized, etc. If the drivers had been led to believe that ride allocation was "fair" (based on distance, predicted arrival time, etc.) or under their control (based on rides being presented to multiple drivers and assigned to the first responder) then finding that it was actually weighted in favor of people driving for Lyft might be a problem for them. This also goes back to the principle of "anyone can sue for anything" as long as it's not frivolous, and this doesn't seem like it'd be considered such. A suit might not be successful, but I'd be surprised if it wasn't at least considered.