They might now be at the point where they have to pick a winner to start integrating. Their engineers have already been driving these things around for years. They probably already have a v1.0 release date in mind.
Uber isn't really a tech company, in the same way Amazon isn't really a tech company. The Secret Sauce(tm) behind Uber is logistics - in managing a highly fluid workforce, dispatching, etc.
Not much of which transfers into this post-human-driver world. I like Uber, but I don't think Uber being Uber really confers a large advantage over new entrants when the autonomous cars become reality.
It would seem to me that, when the time comes, any number of companies run by reasonably talented people with capital backing can start a car service. Uber's edge applies to their human-driver business.
Uber has the strongest brand. Uber's job is probably to build trust, push a convenience and affordability message.
If Google want to hit the ground running with a robot taxi service, they need Uber to be growing into something that my parents might use in parallel with the finishing touches being put on their AI cars.
They might now be at the point where they have to pick a winner to start integrating. Their engineers have already been driving these things around for years. They probably already have a v1.0 release date in mind.