So this seems to be limited to PAID bookings only. Kinda like what I ran into with my Starlux ticket. I ended up just booking JAL award tickets and it let me go in with the record locator and pick seats in advance. Ultimately it seems to be causing a lot of chaos, and I'm laying this firmly at Alaska's feet for their stupid "Simplifying" change that has been anything but, as well as failing to manage expectations.