Making no judgement here. But can your family enroll your son in some ECs that can help build maturity and confidence through experience? Some type of scouts program, and/or hobby that allows him to use his hands?
Also, kids should be engaged in sports to account for our more sedentary lifestyles. Maybe a team sport is not for him, but racket sports (tennis/squash/racket ball), running, age/size appropriate weight lifting, gymnastics/parkour class at a local facility, martial arts…
Building skills with his hands and building strength with his body are key to healthy growth in such a digital world. He can be around peers in person and develop his social skills. The best time to start is yesterday, and now is another great time.
It might be uncomfortable for him to start, but he is so young (8th grade) that if you do so now any hiccups can be natural growth. And this might be better than holding him back in 9th, potentially.
If you build his confidence, his size will matter much less than his abilities.