This appears to be true of Twitter and others as well.
From my vantage point, it appears to be quite arbitrary. And quite concerning in a number of cases, given the centralization of email, docs, etc.
I do make backups of google content every so often.
I guess the irony of making a copy of a cloud set of services data locally, as you may not be able to trust that these services will be there over longer intervals, is either ironic ... or problematic.
It speaks directly to the concept of risk of extended supply chains ... is the risk to your data, and ability to interact with services worth maintaining a presence on the systems?
This behavior on their and related tech giants generally makes me question how much we should rely on them for important things (like permanent email addresses) over time. This has been making me uneasy for a while, and seeing more stories like this is not quelling my discomfort.