Looking at Slafs entire career stats
Juraj Slafkovsky Stats and News
As a 13-14 years old player he dominated the U16 Slovakian league and did ok in the u18
As a 15-16 years old he did very good in the u18 and okish (although small sample) in the u20
As a 16-17 years old he was decent and had no impact in the Main League (although only 4 games sample)
As a 17 years old he was struggling in the Finland main league. 5 goals 6 assists in 35 game but was dominant in the u20
He went from scoring almost 2.5 points a game to like 0.3 points a game. Of course we shouldnt be expecting the same production from a 17 years in a league of men but its pretty clear from what we have seen so far is that this young prospect has alot of learning to do to be NHL ready. He's got some tools and is lacking some others. He needs to work on his craft. Hockey IQ for the NHL is not something easy to learn.
For me if we want him to become a dominant force in the NHL he needs at least 2-3 years of OHL and 2 years of AHL. He's gotta develop his agility level to match his size. He cant take 2 seconds to complete a deke, its gotta be instant and those things you perfect them in the minors not in the NHL.
Like St-Louis said, they want him to be the best in the draft at 23 years old. So we shouldnt be afraid to send him down.