Danhiel I triple checked the train route and hope it will be fine, but thank you for your advice, I will ask sbb at the day of departure.
I also believe it is issue with sbb site\app because in oebbtickets.at I have option to buy ticket Zurich-Dresden for the same route and the same train number EN 40459 - I only didn’t like price, because Austrian site do not use my half-fare card for discount (or I just do not know how to use it). 