What This Means
That makes 400 points an unlock, but not a broad one. The tier is small and mostly Mexico interior inventory. If you want Alaska with any flexibility, 600 points is the better floor. At 600, Alaska becomes the dominant standout, led by Ovation of the Seas and Voyager of the Seas on 7-night Alaska itineraries out of Seward and Seattle.
Use 400 points if you are chasing the single Alaska outlier. Use 600 points if you want Alaska to be a real planning option. That is the tier where the certificate starts to behave like an Alaska certificate instead of a one-off exception.