If malware changes the address in Ledger Live, then this changed address will be what shows up on your hardware wallet, which you will notice when you double check and therefore not sign.
This part made it sound like the altered address would be displayed on the screen of the Ledger device instead of the real address generated by the user.
What I said there is correct, taken in the context of the rest of my post - i.e. an external address you are trying to send bitcoins to.
Let's say I have some malware which will change an address I copy in to Ledger Live when I go to sign the transaction. I copy "Address A", which is my exchange deposit address. I head over to Ledger Live, and create a transaction to send 0.1 BTC from my hardware wallet to "Address A". Just as I go to confirm the transaction, the malware on my device changes "Address A" to "Address B", which is an address belonging to an attacker. This transaction is pushed to my hardware wallet for me to review and sign. The transaction I see on my hardware wallet will show "Address B". When I double check the transaction on my hardware wallet, I will see that "Address B" which shows up on the screen is not the same as "Address A" from my exchange account, and so I will reject the transaction. There is no way for malware to change the address I am sending to in Ledger Live without this new address being displayed on my hardware wallet screen.
This is not the same when considering a receiving address generated by your Ledger wallet, which is what you are talking about. Malware could potentially change the address you see in Ledger Live, but your hardware wallet would show the true address instead, which you would again pick up when you double check the address and would therefore reject it.
