I obviously have no idea how will he develop, but he's en route to join the elite group of youngsters who scored 20 serie A goals in a single season.
In the last 60 years only 3 Under-21 players managed to do that:
Ronaldo (Inter) 25 goals in 1997/98 (21 years, 8 months)
Paolo Rossi (Vicenza) 24 goals in 1977/78 (21 years, 8 months)
Alberto Gilardino (Parma) 23 goals 2003/04 (21 years, 10 months)
Vlahovic, 21 years, 4 months at the end of this season, is right now on 19 goals and he will probably join the above group.