I think you've hit the nail on the head here. I don't think it's a surprise to anyone that Lyft needs money. Both Lyft and Uber are operating at a big loss, and Lyft has been bleeding drivers over to Uber for the last couple of months if the user surveys from /r/lyft and /r/uber on reddit are any thing to go by.
If someone in Lyft management thinks that this leak will help twist Alphabet's arm even a little, of course they are going to leak it.
If someone in Lyft management thinks that this leak will help twist Alphabet's arm even a little, of course they are going to leak it.