Since the BlizzCon announcement of Shadowlands, we’ve seen concerns about whether it is intended that the quest for the Vestments of the Eternal Traveler transmogrification set can obtained from another player’s Ensorcelled Everwyrm mount.
This is not a bug. Access to this transmogrification set is a bonus available to anyone who purchases Shadowlands. While the Heroic Edition and Epic Edition also grant the Ensorcelled Everwyrm flying mount that summons the questgiver Xolartios, anyone who has purchased Shadowlands can interact with the questgiver and earn the transmog set. The quest for the Vestments of the Eternal Traveler will also remain available to all WoW accounts that have upgraded to Shadowlands after the launch of Shadowlands.
The questgiver does not offer the quest and rewards to player characters who have not yet pre-purchased Shadowlands.