I downloaded the Nik Collection v6.2 installer when the update was available and installed it on a M1 MacBook Air 2020. When the installer had done its job, not all applications were installed, those with the new UI were missing. Tried it a few times with the same result.
Nik Collection v6.0 installed all applications though:
Also, macOS’s System Info app flagged them as being fully “universal”: and they all launched without asking for Rosetta. Was unable to test them though, because my test period has expired.