It's hard to get a sense of an entire World of Warcraft expansion from 30 minutes of play. In my short demo, I recreated my main (a Beast Mastery Hunter) and played through the introductory quests from the Bastion zone, a heaven-like plane from Azeroth's afterlife. The minute-to-minute gameplay very much followed the formula of modern WoW questing, with a variety of tasks like challenging specific enemies to duels, helping craft things in timed minigames, and of course, killing 10 rats (well, not rats, but they might as well be).
Further, once the new character has completed the starting zone, the player can then choose to level up to 50 in any previous expansion of their choice—vanilla/classic, The Burning Crusade, Wrath of the Lich King, Cataclysm, Mists of Pandaria, Warlords of Draenor, or Legion. The expansion's content will scale perfectly with the character level, and each is tuned so that reaching level 50 involves playing through the content at a similar pace to a similar level of completion as those expansions offered when they were current content.
The Shadowlands are accessible upon death, where the player-character can roam, and can only be seen by other spirits. The Spirit of Tony Two-Tusk describes the Shadowlands as all grey and dark, swirling clouds. While Uuna was in the Shadowlands, 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.
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.
Claim a covenant's power: players will be called upon to forge a bond with one of four covenants that rule Shadowlands' new zones, setting the tone for their journey through the expansion with a full covenant campaign. As they level up, they'll get new abilities based on their choice, including class-specific abilities for each Covenant—as well as developing soulbinds with specific covenant members, which grant them access to that character's specific traits and bonuses.