[redxdev]

By Google "verified", they seem to mean that the phone runs some tests on the network before actually connecting to the VPN, and disconnecting completely if the Wifi isn't up to par. It would be nice for them to confirm exactly how it works, though.

The VPN only works with access points that the phone automatically connects to through wifi assistant (this excludes any you have manually selected at any point in time). The VPN only works when the phone itself finds a hotspot that you have never selected and decides to connect.