It is their customary response when a person quits the service, the plan is no longer offered etc that the data remains in read only mode for an unspecified period of time during which they do not any longer take payments for the service. This happened previously to people who exceeded the limit for Gmail free storage too. 15GB of storage free with a Gmail account but if you exceed that (say had Google One and exceeded that and then canceled your Google One subscription) your files wouldn't automatically be deleted.

Actually, I just read one of my emails from Google about their change from drive storage to Google one storage. It claims if I exceed my storage limit for up to two years my entire account will be deleted, not just my files. Effective June 1, 2021. I have a consumer account, but I'm assuming there is an equitable set of policies for gsuite/business users.

https://support.google.com/googleone/answer/9312312?hl=en#:~:text=If%20you're%20over%20your,Forms%2C%20and%20Jamboard%20files).