We don't know... maybe we'll see something at Christmas... but if not, there's no telling that there won't be new DLC (this time on console and PC at once). Perhaps they'll keep making new content until Planet Zoo 2 is announced? JWE2 basically had a short time between the last pack and the announcement of JWE3, so anything is possible....
Although, I was expecting a secretary bird (because of the dictionary mainly too, besides markhor was in the dictionary too).... To my mind, it's not the last pack, as this is the game that has been in development the longest (under JWE or PC).... In my opinion, if they were to actually end support, they would have said so by releasing e.g. a bigger package or something else in the game.... As indeed all games have had (something deviating from the norm, JWE = pteranodons, PC = a bigger package)
I personally enjoy the markhor and the baboon, the cat is a nice addition too.... It's nice that the african lampart will be free, because I can't hide, I was waiting for it....
I wonder when we will find out what other animals are in the DLC...