It doesnt seem to be a red-flag. The caller was calling as an Attorney from Google General Counsel responding to an estate request. They followed up with a spoofed @google.com email with their name corroborating the call.

You're missing the point.

They're saying that the least likely part of the cover story is that Google would proactively reach out to you in order to help you personally with the service you are (most likely) paying zero dollars for, and assign one of their most expensive employees to the case.