And still no private IPs?
We hear you. We know this is a problem. Unfortunately, there are non-trivial infrastructure changes that need to happen before we can make progress, but it's high on our list of priorities. Once we can make it happen, we will.
Right now, the proxy linked below is a good solution, particularity for Managed VMs.
,,The Cloud SQL Proxy provides secure access to your Cloud SQL Second Generation instances. ... It is especially useful when connecting from clients with dynamic IP address, such as Managed VM and Google Container Engine applications."
Lack of private IPs has been the single reason why we've not moved our current dbs over. I'm sure it's hard but you're Google after all o_0