The OSMF Data Working Group has removed roughly 9'000 street and 1'000 place names from the Swiss OSM dataset, because there is very good reason to believe that they had been derived from address data from the GWR (https://www.housing-stat.ch/) which at the time was not legal for us to use and currently has the same status, more on that later.
Most affected is likely French-speaking and central Switzerland and naturally mainly such names that are not easily surveyable (which is why they were missing in the first place). Nothing was removed in the Canton Berne as the GWR data for there is essentially the same as the cantonal address data that we have access too.
The best course of action is simply to get off that couch and go out and survey as far as possible what was "lost", it should be possible from comparing http://qa.poole.ch/ch-roads/list-2017-08-01.html with http://qa.poole.ch/ch-roads/list-2017-08-04.html to determine how much your local area has been affected.
Quickly back to the current situation with the GWR. As you may know on July the 1st the revised GWR ordinance entered in to force, unluckily it seems that I was right in being skeptical in http://www.openstreetmap.org/user/SimonPoole/diary/41672 as, as it seems now, the main effect of the revision seems to have been to open up new business opportunities for SwissTopo but even that will not happen before 2020.
All in all this means that until further notice use of the GWR address data on both the SwissTopo WMS server and map.geo.admin.ch (and most other data there) is completely off limits.
Naturally additional political pressure on the federal counsel to live up to their announcement https://www.admin.ch/gov/de/start/dokumentation/medienmitteilungen.msg-id-66... with real instead of Fake-OpenData is more than welcome.
Simon