As a parent of a nationally ranked chess player, these stories always interest me. This young man's rise has been very fast, and particularly so given his circumstances.
Becoming a Chess Master means a rating of 2200+. Given Tanitoluwa's age and the fact that he is likely just now getting access to good coaching, I expect him to reach International Master (2400+ FIDE) without a problem.
Getting to GrandMaster (GM) is much less certain. Every chess player has a limit, and it's not easy to predict what that limit is for a particular player until it is reached. We know many players that were nationally strong when young, hit a wall for a few years, and eventually stopped playing because they couldn't get better. A couple of them were national champions in elementary school but couldn't win their state championship several years later as other players passed them by.
What concerns me is the 10-11 hours a day playing chess, which means that he isn't paying any attention to schoolwork. There are probably less than 50 GM players nationwide who can make a living only playing chess. The strongest woman player, GM Irina Krush has a full-time job because she cannot make a living with only chess. There are perhaps another 200 that can make a living by playing and coaching students like my son.
