From Broadsword Rep:
The only way you can get him now is by doing a level-23 quest called "Glom's Gloom" given by Reeni in Ardagh. This quest is part of the New User Journey line. As part of this change, Stinky's level has been raised to approximately 23.
**** This means you must have a character enrolled in the New User Journey line in order to receive the quest. This quest is also given sequentially, so you must have the quests completed from the New User Journey up to this point ****