Proprietary Rights: AWS Content

Based on AWS's definitions, the response or output from AWS services would be considered Customer Content, not AWS Content.

Customer Content is specifically defined to include computational results that you or an end user derive by using AWS services. This means that when you input your data into an AWS service and receive a JSON structure or any other output in return, that output falls under the category of Customer Content because it represents the computational results derived from processing your input through AWS services.

You maintain control over this content, and you are responsible for managing decisions about how this data is collected, stored, processed, the format and structure of the data, and who has access to it. The fact that the output is structured as JSON or any other format doesn't change its classification - it remains your Customer Content as it's the result of processing your input data through AWS services.
Sources
AWS Privacy Reference Architecture - AWS Prescriptive Guidance