What exactly does “unopened” mean?
For reasons Woot cannot say it’s new, so they call it unopened.
(Please Note: I’m not employed by Woot, but I volunteer to help in the forums.)
I don’t work or volunteer for Woot! (or anywhere else…) but my semieducated guess is that this is excess inventory (for here or for some non-US market), or a model being superseded by something newer, and Bose unloads it through channels like Woot by removing the warranty (note there is only a Woot 90-day warranty, not the Bose 1-year warranty) which lowers Bose’s cost, thus being able to offer it here for a lower price.
Or, it “fell off the back of a truck.” 
Anyway, I just bought one. Seems like a good deal with the additional 25% off.
How you get additional 25% off ?
It was a limited time offer because of Prime Appreciation Days.
Just received mine today. Indeed, they were UNOPENED. They still had the paper pull tab to open the box for the first time. Pleasantly surprised!