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).
I would go further and say you're crazy if you think a Google engineer is going to run code on your data without a requirement in a signed and funded agreement.
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).