[neuralkoi]

This seems to indeed be confirmed over at https://support.google.com/mail/answer/14615114

"Your data stays in Workspace. We do not use your Workspace data to train or improve the underlying generative AI and large language models that power Gemini, Search, and other systems outside of Workspace without permission."

[djhn]

But then if the terms include a vague permission and/or license to use the data for improving the results, the text is factually correct while obscuring the fact that they do in fact solicit your permission and thus use the data, with your permission.