Google’s network security posture was ideal for WFH. BeyondCorp[1] had already been widely rolled out to most internal services and most internal networks in offices had been converted to MNPs: Managed Non-Privileged networks.
The pandemic has been a great stress test for finding the limitations and gaps; like figuring out the remaining use cases for VPN and MNP exceptions, and accelerating the use of data center-hosted VMs instead of desk workstations.
None of this had any bearing on the company culture however, which was and is very office-centric. It’s been clear from the beginning that WFH was temporary.
[1]: https://cloud.google.com/beyondcorp