Can't quote the exact live letter or whatever, but I want to say YoshiP wanted to change the term or abandon its use in future expansions since using it with the Dwarves of the First who are obviously not "beast" men. I also want to say it was to allow for alternative uses of the beast tribe daily mechanic, such as using it with the Arkasodara which may not necessarily deal exclusively with the Matanga of Thavnair, but the entire village with humans/auri. Or alternatively something like the Omega who are certainly neither "Beasts" nor "men".

Don't know if that is actually the plan with the Arkasodara, but again, I want to say it was to give more freedom to the devs on where or how to deploy dailies.