True. I think maybe part of it is a lack of lines, or at least weaker lines? Also this is one of the first entries in which there are several more species being shown as characters, and that causes the design for that animal to become anthropomorphic versus realistic, which TLK generally had animals that weren't either lions or part of the small cast of main characters. Like compare Fuli to the cheetahs during the Circle of Life sequence.
But its definitely been simplified. Lines are much smoother and there's less fur detail, but whether that's an aesthetic or technical choice I couldn't say. The animation will probably get more fluid over time, though, I've watched quite a few shows from this era and that's a consistent development. Especially fur, considering Kion's dramatic mini-mane.