Even if issues with self-driving cars did require new regulation, there's no reason that regulation should favor the cars. Cities and their streets are managed by democratically elected governments. If people like cycling -- and many of us do -- then we can construct the regulatory and physical infrastructure to support it.
note: I'd be glad to register and pay for a bike license if that means more dedicated lanes for cycling --so long as scofflaws get ticketed.
It'll be a long time before buildings are reclaiming space taken by streets.
Irrespective of any s of-driving cars, it's a near certainty that the California mindset of 'regulate everything and we can create a safe utopia' will result in more regulation for non-car personal transportation.
When self driving cars start to become a normal thing, accidents with pedestrians or other cars won't be very likely to happen. But accidents with bored teenagers on small electric motorcycles or longboards... those will be an issue.
Biking is much more legislated in cities like Tokyo than San Francisco, and I expect the latter to follow the former. I don't think the "millenials" of 2040 will be riding their bike much.