Are there any indications that the Sidewalk network can be used to relay other than device control information?
Amazon makes things cheap and easy but not always in ways agree with.
As a counter Example, Canonical got some critique with their "telemetry in the installer", but if you ask me, they did it in the nicest way possible: They told everyone that they want some data to focus developers' efforts where it counts and they let me inspect the json object I was about to send them, so I trust them and sent it to them with a smile.
If you own an Echo device and used it prior to this feature you had already granted a large degree (relative to this feature) of trust to Amazon anyway. It reminds me a little of people who swear they will never use an Echo device due to concerns about eavesdropping but happily carry an internet microphone equiped smartphone everywhere.
We need laws against this shit