He said "one of the best" and post-WJC. Highly arguable, yes, but not completely out of touch of reality. He did manage to score 16 points in 19 games (25 in 29 when playoffs included) in a league where only two players were able to reach PPG among those with at least 20 games.
Exactly, not the best but one of the best post-WJC.
When you look at the whole spring, I think Pulju and Sebastian Aho had the best ppg. It's easier to compare players by statistics, but what they offer outside of them gets more complicated to evaluate. However, I'm sure most would agree that Puljujarvi was one of the most energetic guys in FEL and didn't have bad weaknesses in defending either. And when it comes to statistics I think his roughly ppg average in playoffs was definitely good, only Sebastian Aho and two players from a finalist HIFK were slightly ahead.
After missing most quarter-finals Pulju played seven of his ten playoff games against Tappara, the coming champion, which had a strong defence and the best goalie of the playoffs. E.g. Sebastian Aho made a lot of points while Pulju missed those quarter-final games. Then Puljujarvi obviously had to play at least somewhat injured and he got less ice-time than Aho and Laine. However, the FEL playoff statistics show that the average ice time he had was actually 16,30, which was just a couple of minutes less than Laine's, but a lot less than Aho's 21,02.
I have to emphasize that I don't think Puljujarvi was or still is a perfect player, but the potential is exceptional.