Congratulations on your son’s ability.
However, I quibble with him going after Satriani, Van Halen, and Malmsteen.
The best guitarists say more with less. Tell him to study Vaughn.
Not Stevie Ray. His brother Jimmy.
And, he really needs to have his head on straight and a clear understanding of what morality to have. If he doesn’t have that, he is likely to end up in big time trouble.
Jimmy Page, Tony Iommi, Dire Straits, Hendrix etc. Simple is best. I don’t know how relevant Malmsteen is now that the 80’s are gone but the other guys I mentioned will always be relevant.