The difference is that various functions do not work in Switzerland for the EU devices. For example, Samsung Pay, NFC, Wifi Calling. In addition, these devices are excluded from promotions and actions of Samsung Switzerland AG.
I also had... Swisscom SIM card...
I just used the link for Liechtenstein SIM card :) so it worked and I could register everything with CH address (if it works then I will know when I get the headphones ;)