Just for clarification what happens on the next OTA re contacts:
Software has been exchanged to replace the old contacts backend with a newer one
The old user data remains in your device
A new Db is created, and a migrator runs one time to move all contacts into the new Db (thats the current blocker, the migrator wont start on all devices due to a very difficult datetime issue in the recovery mode)
A flag file is created to not migrate more than once
Google contacts sync is disabled for now
Thats all. No contacts can be lost. In case anything goes really wrong the old database is there, and with another small emergency OTA we can help all users to re-migrate it for example. So we got most of scenarios covered.
I disagree to keep this pending until everything with sync is fixed. This means we cannot release another OTA, or any update to users. This means 16.04 is dead in the water (which it is already kinda) and we come closer to a cutoff date where everything must first work in 20.04 - imagine all of what we have queued now, approx 35 items, if one of them breaks in 20.04 which is very likely, we can again not release.
Also there is no point of saying that this is ok, simply put all hands on 20.04: It still does not have a release date, and most of all a lot of devices might not get upgraded if we cannot motivate the porters to do the necessary changes.
We need to be able to push 1, 2 or even 3 more OTAs before 20.04
