Please provide your source. The Blizzard API tracks all this information and is then made public for the addons. Thats why they are able to “break” any add-on they want. If you want to source your response, please do.
If not, then all you are saying is you are pulling crap out of thin air and just because it came from your brain to your fingertips makes it real.
Blizzard can see everything. They can see every message youve typed. They can see messages youve typed then deleted. They can see who you trade with. They can see when large sums of gold go to a player they’ve never interacted with. They track damage and allow addons to store the details. They split the damage, healing and damage mitigation spells you click. They know every device you’ve ever logged onto the game with and what cellphone you use as well as every cell or internet tower you’ve touched while your blizzard apps were open.
Your argument of, “blizzard doesnt keep that information” is really really bogus.
Simply using your favorite search engine with the term “how does raider io work” will describe how much information Blizzard stores and passes on on the player side of things.