At that age, and this is my experience as a teacher early learning development center and working on my teaching degree
it is the perfect time to introduce the game, the game helps develop critical thinking skills and outside of the box thinking, it encourages players to find different solutions and always changing environments which will help his development in the long term as he will not be used to thinking "1+1=2" instead it helps show there are many different solutions to problems and one must be able to adapt and be willing to learn and fail and then implement what they learned from their failures and successes.
A lot of kids in this day are not able to do such things and it is becoming harder to deal with them and teach them since they are so close minded on many aspects.
That is is why I concur that introducing the game at his age will not only be enjoyable for him and you as well but will help him become a productive adult in society when he is ready to set out n his own cause he won't be "stuck" in a rigid mind of thinking