This skips all the content before the previous expansion to give players the most modern experience from a quest design POV (and to make sure the players are connected with the current storylines). It also ensures new players have a shorter leveling ramp—Blizzard says it will be as much as 70% shorter than it is currently to get from level one to the cap.
This section contains information that needs to be cleaned up. Reason: The death knight realm has already been confirmed to be the Shadowlands. Sylvanas committing suicide from ICC in EoN has already been connected to the Shadowlands. Reword still unclear things, move confirmed things to the main section of the page or remove them entirely if they are already incorporated there.
The Shadowlands are accessible upon death, where the player-character can roam, and can only be seen by other spirits.[8] The Spirit of Tony Two-Tusk describes the Shadowlands as all grey and dark, swirling clouds. While Uuna was in the Shadowlands,[9] she described it as dark and she was unable to see anything, though she could hear people interacting with her in the physical world. From within the Shadowlands, she could see the light of the naaru A'dal who was in the physical world, but it was so bright that it scared her. The moonlight at Lake Falathim allowed her to see a friend in the physical world.
Blizzard's new solution in Shadowlands is to return the level cap to its original value of 60 and to make current content appropriate for levels 50 through 60. New players start at level one, and they all play through a new introductory zone built for Shadowlands based on the quest design lessons Blizzard has learned over the years. Once they play through that introductory experience, they can then level up to 50 to catch up with current content by playing through the previous expansion (Battle for Azeroth) right away (from around level 10).
Shadowy Tormentors inhabit this dimension, and emerge from it to torment death knights such as Koltira Deathweaver. The Lich King originally kept them at bay, but after the Knights of the Ebon Blade left his service, the tormentors are now loose upon them. He even appears in the World of the Dead, as he calls it, riding a frost wyrm during  [73] The Power to Destroy.

Let's be clear where I'm coming from, here: I've been playing World of Warcraft almost continuously for 15 years. (I lapsed for a big chunk of the Wrath of the Lich King era for IRL reasons.) While I understand the appeal of WoW Classic, I am very much a proponent of modern WoW; the game has evolved over time to be more accessible for me to play just a couple of hours a week, as real life now dictates. But I tend to play solo or just with one or two friends on a sporadic basis, which means I'm looking for something very different than the hardcore raiding or PvP crowd.
The Realm of Shadows may be the same World of Shadows as the one that becomes visible when a [Elixir of Shadows] is consumed. It may also have something to do with shadow magic and shades. Death knights, necromancers, and undead as a whole share a strong connection with the Realm of Shadows from many hints that can be seen in-game. In the death knight starting zone, death knights are given the task to enter the Realm of Shadows in order to gain their Deathcharger. Later on, death knights are eventually able to learn the ability [Raise Ally] which pulls their ally's spirit back from the Realm of the Dead and forces it back into their body. Upon doing so, a buff is applied to the player stating that: "A touch of the spirit realm still lingers..." This shows that death knights and necromancers both have a connection to the Realm of the Shadows/Dead to perform necromancy which furthers the idea that they actually are drawing their magical power from it.

The origins of the Shadowlands remain uncertain, but they have existed ever since mortal life first arose in the physical universe. They span all worlds,[citation needed]  including Azeroth, on which Icecrown serves as an anchor to the Shadowlands.[4] There are those who believe mortal souls are drawn into this dark place when they die, remaining there forever. Others hope their souls will go on to a brighter place rather than languish for eternity within the cold confines of the Shadowlands.[2]