DL will almost certainly do with SAS at least some of the things it has done before in successfully getting its TATL-flying partners to devalue miles/points for long-haul redemptions — and even more extremely so with regard to premium cabins.
And for those hoping to use SK points to go CPH-ATL-___ onward DL flight, DL will play a very frustrating role with award availability for those wanting to use partner program points for that onward DL segment (and the feeder DL segment on the return). And if SAS gets into the DL-AF/KL-led TATL JV, it’s probably going to be on the worse side of things with regard to using SK points for TATL flights.
For those who just want to fly on wholly SAS itineraries and don’t want to go beyond ATL — or other SAS gateways — in the US entirely on one award ticket, it probably won’t be as painful (at least as soon) as for those who who want to continue or begin flights beyond the SAS gateways in the US.
UA is much, much more generous with “standard” award space being made available to its partner airline programs than DL is. That big difference compared
to DL is part of the devaluation that will hit those wanting to use SAS points for award travel using a US partner operated flight to and from the SAS gateways in the US.
For what it’s worth, there is quite the history between DL and me — and not just as a customer. I have confidence in DL’s ability to fleece customers — including customers of partner airline programs — and get away with it.