Nobody knows. I know a kid who fit your basic profile in 8th grade and is now a HS senior throwing 89 and on his way to a D1 college. I know another who is also a senior, throws around 83, and is going to college for pre-med, not baseball. I know another who never grew an inch after 8th grade and never really got much quicker as a pitcher. But he's still a decent player and loves the game. And I know one other kid who quit baseball after a great sophomore season on varsity and now spends most of his waking hours smoking weed.
RJM gave you good advice in your other thread. It's great to have long range goals, but short-range goals are more practical and easier to work on. Get on a training regimen and get better every week. Spend time working on core strength and conditioning. Play another sport. And most importantly, focus on your academics and hit the ground running when you get to high school next year. Set a target GPA and reach it every semester.