Re: New here :)
He is going to be great when he is big enough to properly address that kit. In any case, if he sticks with it he will be great cause he has a nice head start.
There are some bad habits forming; the stiff wrists, the seating position, the distance from the kit. maybe he has another more appropriate kit; if not I would get him into a smaller setup; maybe even a jazz kit and get it more ergonomically setup for the little fella....with some attention paid to the fundamentals and some focus on more appropriate technique he will take off and blossom.
The playing at this moment, honestly, is what one would expect from any beginner. The song I watched has it's moments where it is close, but it would not be able to be played with a band. These videos are great to ascertain the weaknesses and discuss them and review with the teacher.