I upgraded one of my Apple TV 4K units to 13.2 and ever since it is constantly hitting the internet. Usage is something like 500MB per day. I use my Apple TVs for one thing, streaming data from a local Plex server. The unit is not signed in to my iTunes account and updates are turned off (or to manual only). This data usage did not occur with 13 and only began with 13.2.
This should really be TVOS and not Apple TV hardware, but I did not see that as a topic option.