Can you provide a citation about that with AWS and its customers? Amazon itself, I have no problem believing (and have seen it in action. However, AWS is run separately from Amazon('s storefront, specifically).
If AWS were really aggregating customer's data stored in AWS' platform, I think we'd be seeing a lot more about it in the news. And there would be a lot more than just Walmart advocating against its use.
Is that relevant? Nobody can provide such a citation for Google Cloud Platform either; the discussion is entirely around reputation of the parent company, not what the company claims it does with cloud services.
AWS mining their customer's data is a huge liability for their cloud business and a blatant violation of their service agreements. Something that would fundamentally break the concept of using cloud services like AWS or Azure.
This is why this comparison doesn't make sense. Google Analytics is a 3rd party service where you have no control at all of your data. You put a script of your app, and then you basically funnel data to them. That's it.
Using Pinpoint, in this case, is the equivalent of using EC2 and S3. You can control the flow and the lifecycle of data (deleting data forever, for example).
You should be able to trust that your customer data is safe there, otherwise, why use AWS at all? or better yet, why use any public cloud infrastructure provider at all?
If you're concerned about that, you probably should build your own self-managed server infrastructure.
There is one exception to this that I know of: AWS Rekognition will re-use the faces you scan with it for training and "to improve and develop the quality of Amazon Rekognition and other Amazon machine-learning/artificial-intelligence technologies." That's so vague, they can reuse it anywhere Amazon (not just AWS) uses machine learning.
If AWS were really aggregating customer's data stored in AWS' platform, I think we'd be seeing a lot more about it in the news. And there would be a lot more than just Walmart advocating against its use.