Just another data point;
We had return tickets from IAD-CPH on July 9 (had flown out a month earlier before the strike). Award tickets in J booked through SK.
The flight was cancelled at 3AM Eastern on July 8. I didn’t wait for the automatic rebooking process but called the for-stranded-passenger number right away and got through after just a 5 min. wait. I suggested rebooking with LH via FRA. Since it was an award ticket the agent couldn’t process it but needed the EuroBonus office in Sweden to book it… and they weren’t open at that time. I did receive the updated itinerary right away but with the flights listed as Y class. The agent said the EuroBonus office would fix this. To my great surprise they did. Received the tickets, booked in J on LH, around Noon and flew home the day after.