The list is updated at irregular intervals, depending on the assessment of the pandemic so, yes, unfortunately, it is difficult to plan.
The current version of the rules of entering Switzerland, to do with any Covid restrictions, and also with links through to the immigration rules, can be found here, in English.
https://www.bag.admin.ch/bag/en/home...nreisende.html
The travelcheck is quite convenient, to check the individual situation of any potential traveller. Of course, this is "information only" and not binding, but still helpful.
https://travelcheck.admin.ch/home