SAS is relevant because they purport to set out at least part of the current USG rules, applicable we can fairly assume to all airlines boarding passengers bound for the U.S. Don't think the Feds have special rules for the Scandinavians.
Further, my understanding has always been that the detailed rules for screening passengers are not public. So the information provided by SAS may be the best we'll get.
Whether you like it or not, whether or not it's reasonable or comports with natural justice, you should not be surprised if there are now issues at check-in if your passport does not show where you have been for the past 14 days.
The message is: Be prepared! Don't assume that tweet is a one-off.
Well in that case fortunately my next two trips are to Australia, where they have to admit me even if I've been to Mainland China in last 14 days.
The trip after that is Japan - how do I prove I've not been to Hebei or Zhejiang? My HKID entry-exit record doesn't say where I'm going.