I always liked that texture of hairstyle on Monica, although I'm perfectly fine no matter what style she sports, from 'fro to braids and everything in between. I don't know this for a fact, but in my head canon, I think they were probably trying to then modernize her style to something more in line with the "Clair Huxtable" look, played by the amazing Phylicia Rashad. Of course, Ms. Rashad is biracial, if memory serves, hence the texture.