So the “Frequently Asked Questions” section of the play wow website (https://www.playworldofwarcraft.com/) end with this segment.
What’s east of the Eastern Kingdoms?
You’re not yet ready for the answer to that question.
Now something to consider is that the questions were made by Blizzard. Thus it leave the question… what is East of the Eastern Kingdoms? Shall the Dragon Isles, previously assumed to be placed in the area off to side of Northrend and above the Eastern Kingdoms, end up there? Or is it Blizzard teasing that there is still room on Azeroth for continents, with the door open for the other side of Azeroth to be explored?