Petite maj pour le vol
Upon completing a quest contained within the « The Last Sigil » storyline, you’ll be rewarded with Memories of Sunless Skies. This consumable item allows all characters on your account with Expert Riding Skill to fly in Bastion, Maldraxxus, Ardenweald, and Revendreth!
Voilà, au revoir les spéculations
Blizzard said:
The « to purchase » wording in the Shadowlands Flying blog was only there to indicate that the player will need to have trained Expert Riding. The vast majority of active players have had that for ages, the wording was just included for the sake of accuracy as Expert Riding is not automatically granted upon unlocking Shadowlands Flying.