Even if they don't train on your content, Google reserves the right to use it for improving their services in other ways:

“ This license is for the limited purpose of operating the services, which means allowing the services to work as designed and creating new features and functionalities. ”

https://policies.google.com/terms?hl=en-US#toc-permission

The training exclusion has always been a distraction. These service providers have plenty of other uses for your data.