Sounds to me like there's only really 3 primary planes in the grand scheme of reality: the main universe (the Great Dark Beyond), the Twisting Nether, and the Shadowlands. The rest are like side projects spun off of those.
why De Other Side not in list?
The Zereths are also not mentioned. Yes we have only been to Zereth Mortis, but we know that each of the 6 main cosmic forces has a ZerethZereth:Mortis - DeathLumen - LightOrdos - ArcaneVitae - LifeUmbra - VoidTumult - Fel
Not all dimensions are equal in size and power. The Shadowlands did a really bad job of projecting its size, considering the 4 covenants but that there are supposed to be far more.
They forgot to mention the Twilight Zone.
This is actually interesting to me, while story devs are known to forget things I don’t specifically think that is the case here, seems like they are consolidating, the existing realms down to a more coherent wrap around VS. there are sooooo many and infinite amount even.
PlatinumWow's content is SUCH high quality, yet is criminally under-watched. Great to see the signal boosting by Blizzard as well as Wowhead!