They also learned their lesson from the patches on the first few expansions. They generally extend them like this with major patches before they open them up. If you were here for BC and Lich you’ll remember they’d usually bring them up on time only to have them crash. I remember in B.C that it would be down for days at a time, which was a royal pain if you died due to the crash. In BC it would crash, come back up, crash, on repeat. I remember that I just took a few days off when I took a trip and didn’t play for about a week.
In order to avoid that regularly test the game before opening realms.