Data points to followers that are class-specific, which you’ll get from quests in Legion. These will likely be tied to your Class Order Hall.

Thassarian / Koltira Deathweaver – Class: Death Knight, Quest: Always a Knight of the Ebon Blade, Zone: Azsuna
Koltira was raised into undeath as a Death Knight after being slain by the knight, Thassarian. Despite death at Thassarian’s hand, they treated each other as friends up till they found themselves on opposing sides in the Battle for Andorhal. In this battle they held a truce that prevented outright hostilities until Sylvanas Windrunner became involved and he was cast into the Undercity by the Bainshee Queen. When asked about this Koltira refuses to speak any further.