Yes, here is the official statement:
> Consumer Gmail content will not be used or scanned for any ads personalization after this change. This decision brings Gmail ads in line with how we personalize ads for other Google products.
https://blog.google/products/gmail/g-suite-gains-traction-in...
Edit: The problem with google is that they collect a lot of data they can abuse, not that they are particularly known to abuse data. So the danger is that their policies change while still having your data, then there is nothing you can do.
I’d imagine Google could build up great profiles based on metadata alone - which domains email you, which you email, etc.