I'm sure someone will correct me if I misstate. In the US, TN are the same as Service Bulletins, recommended but not mandatory.
Manufacturer would have to ask their country of manufacture to issue an AD, then the US FAA would follow with a US issued AD.
Then it becomes mandatory.

Some TNs allow for modifications or additions to the basic airframe, like "spin kit", or change the brake to hydraulic disc. If you don't want it, you don't need to install it.

BillT