I promised that I would write an update when Ledger support responds to my question so here it is.
I sent them a message yesterday asking if they will refund tax and shipping costs to users who brick their devices following firmware upgrades. The automatic email that my message was delivered and a ticket was created was received at 9:50 CET. After that, it took them only two hours to reply back. I got an email from them at 11:51 CET.

But since they didn't answer all my questions, I sent a second email in the evening asking again about the charges.
I received a reply from the same customer service representative this morning. He told me that if the Nano breaks while it's still under warranty, they will exchange it for free. If the wallet breaks due to a software issue, it will always be exchanged for free. There is an unlimited warranty for software problems according to James. Since a malfunctioning device after a firmware upgrade is surely classified as a software problem, your hardware wallet will be replaced even if the original warranty expired.

To be fair, he again didn't directly answer my question regarding the tax and shipping charges. I can only assume that Ledger covers those as well, but I am missing the needed confirmation from James.
In this particular case, the response time was really good.
I think it's a positive thing that if you brick your HW due to a fault of their own, just contact the support and you will get a replacement for free.
This gave me an idea for another test I am planning to perform with their support staff, but more about that another time.