Earning your Dalaran Hearthstone in Shadowlands is rather simple. If you skip the Legion storyline as you're leveling your character or you take a level boost, there is another way to earn direct teleportation to Legion's Dalaran.
With the launch of 9.2.5 and the release date of Dragonflights still unknown, players will look to level and play alts to pass the time. It's common for those alts to miss some of the content during the leveling process.
And with the promise of Season 4 rotational raids from previous expansions, it may be beneficial to have the Hearthstone for Dalaran.
Where to Find the Dalaran Hearthstone in Shadowlands
First, take the portal in Stormwind or Orgrimmar to Legion's Dalaran. Then you need to talk to the Innkeeper Amisi Azuregaze. She's at 49.6 39.6. Talk to her and she should have a line to give you your Dalaran Hearthstone.
It's as simple as that, and if you ever were to lose it, head back to her and she can give you a new one.