Not necessary. When not connected for more than a month, a device gets declared insecure and stops its core function or gets annoying until you allow it on the network again. Downloading new firmware is only possible by uploading metrics, and provides all kinds of new 'experiences' of course.

In 2 years, a standard fridge will start blinking its inside lights and show 'error' on the temperature display if you don't let it connect.

If it runs on the their network network and not mine, then any activity will be tied to their IP and the incorrectly correlated with their usage.

So - my privacy stays intact as long as I don't link the device ID with my name or personal details (review that warranty card before sending in, does it have unique ID? watermark/non-visible tag) - hmmm, this sounds like a bonus - I get the "smart" features and don't have to worry...