My flight is also on Thursday and just jumped to 1600... At this point, I mentally gave up on an upgrade. 5 seats are taken, the rest still show as free.
I opened an Expert Flyer account just as curiosity. The flight shows the same reserved seat number as trying to book a flight through SAS, with the difference that all other "free" business seats are "Premium + Paid", which I don't really understand what it means, but they don't seem to be technically taken, as they would show on a different category if they were.