My current understanding (it changes, and I may be out of date already) is that the new cert requirement starts tomorrow, and from Tuesday or Wednesday it'll be announced how those vaccinated abroad (with vaccines certified by the EMA) can get a Swiss cert.

So I'm not expecting any major hassle for (vaccinated) tourists. But I think a "wait and see" attitude over the next few days would still be helpful.

https://www.admin.ch/gov/en/start/do...-id-85035.html (useful info near the bottom).