A Complete Catalogue Advancement Bug

I was playing on my survival world with the 18w44a snapshot, and I tamed a horse. When I tamed the horse I received the 'Best Friends Forever' advancement but I also recieved the 'A Complete Catalogue' advancement. I have not even seen the new cats or ocelots in this world yet, and when I look in the advancements tab it says I have found 10/10.