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).
Keep raising the level cap but crunching how much experience is required per level as you do. This is the approach WoW has historically taken. But as this happens, levels start to seem meaningless. You gain them ultra-quickly, and only a smattering of them actually introduce new abilities or other perks. It also means that you blast through the leveling content at such a pace that you never finish individual zone stories; you only finish a small portion of an area before you have outleveled it and are ready to move on.
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.