While Rowlet start out as a dual tpe Grass/Flying, I have a hunch that he MAY change up to Grass Fighting. My theory is based on his official description.
"Rowlet can attack without making a sound! It flies silently through the skies, drawing near to its opponent without being noticed, and then lashing out with powerful kicks."
With Rowlet being a flying type, it's kind of odd that they mention that he kicks to attack. They DO go on to mention his razor feathers he can shoot, but I still think he may muscle in on Hawlucha and Blaziken's territory as fighting birds.
"Rowlet can attack without making a sound! It flies silently through the skies, drawing near to its opponent without being noticed, and then lashing out with powerful kicks."
With Rowlet being a flying type, it's kind of odd that they mention that he kicks to attack. They DO go on to mention his razor feathers he can shoot, but I still think he may muscle in on Hawlucha and Blaziken's territory as fighting birds.