As I have started managing a 2nd team after leaving it behind after creating it a few months ago, the ‘free’ youths in the unseen list would be allocated to the additional slot(s) when the youth association is upgraded.
Most youths would be around 4* quality these days.
However, when the first upgrade was completed yesterday, the additional free youth has a max quality of ‘only’ 26.2%, which would be even lower than 2* as long as no training is provided.
For managers who want to get more funds by selling the youth in day 1, maybe upgrade the sooner the better;
For managers who want to get some really low * 18yo for draw manipulation, then maybe upgrade as late as possible.