There is no difference between the models sold by Swisscom and the others, including those sold by Digitec. The only difference is the price, which is always overpriced at Swisscom and hidden in the subscription fees.

I ordered it, and I can confirm that the device I received has Wifi calls, and that it works (not great, but it works)

Thanks for the info
I'm suspicious because I've already bought a Samsung S8 edge from melectronics which didn't have wifi calls, the device came from Germany... I want to be sure that this one has them, otherwise the network at home is cut off