Interesting - never heard of that but would love to know if there is a correlation.
100% is. Its been studied and written about at length, its called the Relative Age Effect.
Broadly its a compounding 'issue'. Those who are relatively older (especially a a young age sept vs August birthday is huge) appear stronger, faster, etc.
As a result they are more likely to be picked for teams, and then benefit from more practice, coaching and game time. So the gulf can widen.
As a recruiters are aware, in sports where size is a massive factor e.g. rugby, the more sports science driven recruiters are looking at 'bio-banding'. Basically grouping by weight/size. Then they get a better idea id 'Jonny' is actually good, or if he's just the biggest in his year.