In the absense of a published and agreed standard, every approach is unilateral. My company is taking a similar approach - disconnecting from external NTP servers on 31st December, stepping the change in gradually, and reconnecting when we're "right" again.
Google have never been in the NTP business - there's no reason for them to have worked towards a concensus on this. But when a company their size makes their approach publicly available to all, it starts to pave the way for a consistent standard for everyone.
Google is in the NTP business. Chromebooks sync time from their servers, android devices can (but also from carrier provide time signals), and for hosts in their cloud services.
Google have never been in the NTP business - there's no reason for them to have worked towards a concensus on this. But when a company their size makes their approach publicly available to all, it starts to pave the way for a consistent standard for everyone.