You can check yourself from the app:
Services > Devices on Network > Manage
And it will show all of the MAC addresses connected, and recently connected. Even remotely if you are not logged into your network.
You also can see the *plaintext* password to your router from this app.
Services > Your WiFi Network
Which means a nation state also can remotely login to your network without you knowing, and otherwise is bad for security if passwords for millions of homes are plaintext.
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Moral of the story is that even if Apple eventually fixes this, the other side of the tracking that nation states could do could be done at the ISP firmware level. To solve this kind of attack, either allowing open firmware or new legislation is the only to stop this. (Which when has privacy legislation ever happened... is another question for another day).