It actually means the opposite. It shows that draft eligible players with late birthdays from Sep 16-Dec 31 are at a big advantage compared to players born Jan 1-Sep 15.
The reason for this is obvious - players born Sep 16-Dec 31 don't get drafted with the Jan 1-Sep 15 kids of the same birth year. They get drafted with the following birth year due to the NHL's late-birthday cut-off, which is intended to ensure the players legal adults by the time they enter NHL training camps.
Basically the late-birthdays get an extra development year to show their stuff. Statistically, 2001-born late-birthdays like Lafreniere, Lundell, Rossi, etc... should be compared with other 2001-born kids, most of whom were drafted in 2019. Comparing their production uncritically to that of 2002-borns like Stutzle, Byfield, Raymond, etc... will lead to the late-birthdays being overrated. This happens every year on HF as there is a tremendous misunderstanding of what it means to be a late-birthday.