Ok 3 posts for one day it seems.
I just saw that there was a Blue Post clarification on the requirement to have Battle for Azeroth in order to participate in Tuesday’s battle. @watcherdev said in an interview with Forbes back in June that you would need to have the expansion. Apparently someone realized that you don’t. Why it took a month and a half to fact check statements made about the expansion. Unless it was a change decided recently. As it is I purchased it Sunday evening. If I had known, I would have waited until this coming weekend.