I have a sneaky feeling, although haven't checked, that most of that goal involvement from Kulusevski is under Conte and at the very start of last season. He went through a phase lasting most of the 2nd half of last season where he was anonymous most of the time. He became easy to defend against and very predictable.
If he can shake that off and adapt his game, he could rediscover the form we saw at the start of his Spurs career. But he was already falling out of favour towards the end of last season.