My best guess is this means they got the all clear from PSE, but Tesla hasn't done their testing yet. There should definitely be someone qualified to do the testing in one of the Seattle (or Portland) area service centers, so it's just a matter of when they can send that person out to do it. Then, if everything looks fine, or at least good enough to open (~90% chance in my experience), they will go live that day. It may still take a few hours, days, or weeks for the supercharger to appear in the Nav and on the Tesla website.Ok, transformer is energized, light pole is lit, but Tesla stalls are still dark. Hopefully they commission it early this week!
There is another possibility that the supercharger has already been tested, but they shut the power down for some other reason. This is often because they want to pave or paint the area, or it could be because something went wrong in the testing and they need to replace a part or something like that.