Sorry for the late response, forgot to reply to it.
For the sake of the debate, let's say that what you're saying is correct, that the rate of his goal scoring is unsustainable, and that the amount of goals he scores next season is in line with his xG; That would still put him up as one of the highest goal scoring attacking midfieldes in the league, ahead of the likes of Bruno, Rogers, Gibbs-White, Maddison, Odegaard, Maddison, Kulusevski, Kluivert, Foden and more. From what I can find, only Palmer is ahead on xG, so he would still be scoring more goals than most attacking midfielders in the league. And this is if that goal rate actually is reduced to his xG. To me, it seems more likely that he is going to continue developing and improve further with a chance of increasing his goal rate for us even further, partly because he would be playing with better technical players in Bruno, Amad, Zirkzee (and hopefully a new technical striker), but also because he has been steadily improving across his time for Wolverhampton, and looking like he is just getting better and better.