Pre-season doesn't freaking count. Are you joking with this shit. Any NHL scout will tell you there is very little you can glean from pre-season, let alone 3 games.
And I never said confidence wasn't a factor. He definitely got better and better as the season kept going, and that's definitely because of the confidence. But he had jump in his step from game 1 of the season. Note that Lafreniere has been in the top 6 multiple times in prior years and still did very little with it. The biggest difference this year was his baseline physical abilities. The coaching staff recognized it and were confident he could succeed, and in turn, gave him confidence. But without the baseline physical tools it doesn't matter how confident you are, you aren't going to do much.
Do you actually think that if you staple Kakko to the top line for a whole season, that he's suddenly going to be a 50 point player, without any improvement in his current physical tools?