But it's important to connect them to the Internet, so that they can receive security updates...! 😅

If you design them so that the temp control is not in software you should be fine.

Don't even buy a freezer that has a remote control. Especially not for freezing life critical supplies.

Seems logical, but there's a valid reason why these fridges are connected, at least for reading data (not so much for controlling).

European law dictates that things that can spoil due to heat must be stored at the right temperature. And therefore you must register the temperatures of each refrigerator at each moment to have a valid proof of compliance.

A simple supermarkt already has 50 or so appliances. And supermarkets are usually chains with hundreds of stores. So you can imagine the need of having to monitor temperatures centrally. I can imagine that for medical use, the rules are even stricter.

IIRC they are locking them into a defrost cycle that would normally heat up the coils for a minute or two, just long enough to melt the frost.

For that, all you need is temperature sensors. No remote control necessary.

Fair point but does controlling the actual temperature need to come into play in these cases? I guess it wasn't an issue before so it was just a feature to add easily and all that.

Sure, but you already likely have at least somewhat secured network around for all the other stuff you do and a computer to store those logs, no need to go trough the public internet for that data. Unless that's some cloud based service too, in which case leaving the devices open like that is even more reckless than having Joe the delivery guy plugging the cables in after hauling that fridge up to 3rd floor.