So I have a team of stars, and I always complained of having no decent youth to rely on, no better than 2 star potential!!
So year is 2029, I check my Youth team out and got.
Probably a good bunch that, as best as I have had for a while.
Then I went on to sell all the stars in my team, build a team full of extremely young regens and go at it all again. Once I sold all my good players, I checked out my Youth team again.
Some of my youth team are sitting in reserves, but the ones still there, now look at their star ratings..
That is the effect of an extremely good squad can have on star ratings of your youth, and of cause I assume all scouted players.