Baby led weaning bad??

My son is 9 months old and when he was 8 months I started him on table foods. I did research on the topic of led weaning and felt pretty comfortable with the foods I gave him. He got to a point were he refused baby food so I quit giving him any. Well my SO's grandma told my SO that because he doesn't have any back teeth he'll get in the habit of chewing with his front teeth? And she gave us a ton of purees. We go to her house once a week for dinner and last time she was determined to feed him baby food even tho she knows he can eat what we eat?? Is what she said true? I heard of people starting led weaning as early as 6 months so it just doesn't make sense to me. Any advice welcome!