Why does that need to be centrally monitored? All the information is local to the refrigerator and the rules about what to do are not dynamic. A refrigerator knows it needs to kick on if it gets too warm. Why does it need to call in to a server to ask for permission? It makes no sense.
All you’ve done is create the possibility of one MASSIVE system-wide failure for the price of a circuit board in every unit that costs a few bucks and that is inevitably going to be there anyway.
Principles aside, defrost shouldn’t be available remotely, even if all the other stuff is, because the freezers have to be emptied and that can’t be done remotely.