The Burning of Teldrassil (Part 1) is now available in World of Warcraft: Battle for Azeroth Alpha.
The first step for Alliance players starts in Stormwind Keep by grabbing the quest A Short-Lived Peace from King Anduin Wrynn. He sends you to the port to take a ship parting to Rut’theran Village. There you talk to the flight master to fly you to Astranaar.
The Horde has decimated Astranaar, and you are left to release the spirit of the fallen sentinels. Waves of wisps keep heading north, heeding Malfurion’s call. Once you arrive near The Master’s Glaive, you find Sylvanas and the Horde rooted.
Malfurion slays her troops single-handedly with the aid of wisps, and Sylvanas retreats back to Zoram’gar. Malfurion then asks you to go meet with Shandris Feathermoon in Darnassus. That’s the quick story of The Burning of Teldrassil (Part 1). The story ends abruptly. It is possible more might be available in a future patch.
However, the days of Alpha testing are drawing to an end — according to our PAX East 2018 interview with Daniel Stahl. He said Beta testing is starting soon. I wouldn’t be surprised if we get to see the full Burning of Teldrassil storyline in the PTR by the end of June, considering release date is August 14th.