Was lange währt wird endlich gut.
swisstopo has now provided FAQ to their terms of use that clarify that central attribution of their datasets conforms to their requirements. See https://www.swisstopo.admin.ch/de/home/meta/konditionen/geodaten/source.html point 6.
Thanks to everybody that has worked on this over the last half a year, in particular Raphael Bovier from swisstopo, and everbody unknown working on the issue there, Benedikt Hitz and Mathias Stürmer from the University of Berne.
If somebody wants to use a specific dataset it should be added to the Wiki contributors page as we have done on previous occasions. If you would like to propose an import (right now I wouldn't know of anything that is urgent), please follow the import guidelines https://wiki.openstreetmap.org/wiki/Import/Guidelines
I'll be updating relevant documents and posts over the next couple of days, so don't be surprised if their is a bit of inconsistency right now.
Simon