In response to an earlier question, the lounge (and several floors in the Pike St. Tower) is closed for renovations. This is a good thing, as the Pike St. Tower is pretty dated compared to the nice, new Union St. Tower. Just wish the Sheraton would communicate better about this.
I've seen several properties "announce" this type of closure on the "announcements" page of their website. Just checked this property and no announcement. In fact, the Sheraton Seattle is doing just the opposite as they are promoting their Club Lounge:
Sheraton Club Lounge
Located on preferred floors, Sheraton Club guest rooms offer upgraded amenities, free bottled water, and complimentary fitness center access. Club guests also have special access to the Club Lounge. A relaxing, upscale space, the Club Lounge offers complimentary breakfast, afternoon hors d’oeuvres and a variety of beverage options. Take advantage of the private Club Lounge where you can connect with friends, meet with your team, or simply relax by catching your favorite TV show. Need to get some work done? A copier/fax/printer and complimentary office supplies are ready to go.