i just noticed today that when i used Ultimate Battle-Training Stone - Item - World of Warcraft which level up your pet to lvl 25 that it now counts towards the achiements since i got the achiement Rookie Pet Group - Achievement - World of Warcraft and got 1 counted in Pro Pet Group - Achievement - World of Warcraft
these can be bought in dalaran for 60 Polished Pet Charmer - Achievement - World of Warcraft which first come when BFA is released but for those that have stocked up on them from the old pet charms then it might be a good way to use them now to get the achiements 8-)
i dont know if this is intended or not so i'm not sure if this should be here or in eploits but please move the thread if it's not in the right place.
hope someone can use this.