Earlier quoted context omitted.
Google states unequivocally in its Cloud privacy documentation: 3. Know that customer data is not used for advertising. You own your data. Google Cloud does not process your data for advertising purposes. https://cloud.google.com/security/privacy/
But they may process it for non-advertising purposes? That feels... flimsy
I believe usage for ads is highlighted on the non-legalese privacy page because it's a common question/concern, but the terms specify that data can only be processed as requested by the customer (IANAL, but that's my read and understanding as a Googler who works on Cloud infrastructure).