Arriving with SAS from CPH this upcoming week. I'm not sure but I think SAS arrives in the South Satellite.
I would very much like to visit the B terminal close to gate B1 since Bose has a kiosk store there (where I would like to purchase the QC2 headphones).
So my question is if I can access the B1 gate area when arriving?

The Concourse B train stop has been halted during the renovation of the south satellite train system. They did this to Concourse C (for renovation of the north satellite train system) but eventually they reopened it. Unfortunately, this won't happen this week.

At present, there's no way to get to Concourse B without clearing security in the main terminal. And the TSA won't let you through unless you have a boarding pass.

If and when they reopen the B-concourse train stop, you would still have to clear security at the South Satellite as a transfer passenger. And it's unclear whether they would let you do this unless you were truly a transfer passenger. If you don't do this, then you get dumped into the main terminal with no chance of getting back into the secured part of the airport.

The train is segregated into arriving international passengers and domestic passengers. And you can't pass from one to the other unless you've cleared security. The reason is that during customs you (in theory) had access to items in checked luggage that may or may not be acceptable as hand-carry items.

Thanks a lot for clearing things out. I have printed out the addresses for the Bose stores in Seattle city center, will go there instead and hope that they have the QC2 in stock