Doesn't go back to when they launched premium class, but not brand new either.. Been noticing it at least a few weeks, if not a few months. If I had to venture a guess, I'd say that as part of the merger with VX, they changed how they coded the seats in their system to align the AS premium and former VX MCS seats, and that data, when sent to Expert Flyer is misinterpreted to show the seats blocked instead of the former Premium/Paid icon they used to show.. Again, that's just my guess as the timing seems to match the late-April date, and no real reason I can think of as to why Alaska to want to have those seats shown as blocked for external systems but open on their own. Not sure if it's AS' or EF's issue to resolve, but am also pretty sure neither of them realizes its an issue.