Hunter pets are being streamlined in Battle for Azeroth. You can no longer freely choose the specialization for each of your pets because each family has a set specialization. Pets from all three specializations — Ferocity, Tenacity, and Cunning — will all deal the same DPS and have the same amount of baseline health and armor, but they will be differentiated by new and powerful abilities. Additionally, every pet family now has some a special family ability (even if many of them are duplicates of others). All Exotic pet families (Beast Mastery only) have at least 2 special abilities.
As we are still in beta, none of this is final. This post will be updated whenever new pets are added or changes are made.
Latest Update (June 28): 10 MORE STABLE SLOTS!