I think you're thinking of Cloud SQL v1. v2 is "just" a managed instance of MySQL 5.x (I think you can still lock to 5.6 if you're not ready for 5.7). The MySQL team at Google already open-sourced the semi-sync replication, etc. so it's not like it was ever "crazy" anyway.
Disclaimer: while I work on Google Cloud, I don't work on the Cloud SQL team.
