That doesn't seem related to privacy, nor is it necessarily anchored in reality (most monitoring APIs don't incur extra processing, and I haven't seen any research indicating that reporting of new ancillary data is a huge factor in bandwidth consumption).
In Designing ancillary APIs that provide new information it's mentioned that user agents should enable users to turn off these APIs for bandwidth or processing reasons.
That doesn't seem related to privacy, nor is it necessarily anchored in reality (most monitoring APIs don't incur extra processing, and I haven't seen any research indicating that reporting of new ancillary data is a huge factor in bandwidth consumption).