Hardware wallets are offline wallets. It means they are not connected to the Internet when you are using them to make transaction.
This is incorrect. Although you can use a hardware wallet offline, most users connect it to an online computer. Ledger nowadays can even "call home" and
send your recovery phrase to Ledger.
Thank you for the link. I wasn't aware of the existance of this
feature/service.
This is unfortunate because the only reason why anyone would buy a Ledger wallet is their promise that "your seed never leaves your device". Obviously, this is no longer true.
Now that we know that a third party service or entity can access your seeds (unencrypted) we will never be sure about how safe our wallets are.
I just hope this option doesn't exist in older firmwares.