Rumor is Tatsuki asked for more money & Kadokawa told him to kick rocks. Considering his pedigree is far less established than a lot of the directors Kadokawa works with, & how Japanese corporations in general are highly resistant to bowing to pressure from employees, I'm really not surprised.
Kemono Friends didn't impress me at all, so I may be a poor judge, but I have to wonder how much Tatsuki even had to do with its success. Most of the praise for Kemono Friends seems built on the scenario and memes about the characters, neither of which Tatsuki created. If his directing were red-hot I have to imagine the presentation would have been better from the start, even with the exceedingly low budget they had.