Ah, now it's almost mid-February 2021

I have found a small report on this (from February 2021). The statement from AVM is quoted:

"Thank you for your enquiry and for not forgetting our FRITZ!Box 6850 5G. :) The 5G rollout in Europe has been delayed overall in 2020, including technical adjustments. In order to offer users of a FRITZ!Box 6850 5G a significantly improved compatibility to the 5G NSA networks and thus ultimately a higher longevity of the product as a whole, the market launch will therefore probably not take place until spring of this year."

Link to:
https://www.teltarif.de/avm-fritzb...

I wrote to AVM Support today:
"The market launch of the FRITZ!Box 6850 5G is expected to take place in July/August. You can get the FRITZ!Box and other AVM products in your area from well-stocked electronics retailers, in stores such as Saturn, Media Markt, Conrad, Expert, etc., as well as from online shops such as Otto, Amazon, Alternate or similar.
Based on the shops listed, I assume that this statement certainly applies to Germany. But hopefully it should quickly spill over into Switzerland as well. Let's hope that this time it really gets going.

There is news:
https://avm.de/presse...

The FRITZ!Box 6850 5G will probably be launched in late 2020, early 2021.