The holdback issue only comes into play when kids being held back are taking roster spots from kids playing age or grad year appropriate.
If there are 100 roster spots/ tuition assistance and 20 are taken by kids whop are heldback, that reduces an age appropriate players chances of getting into certain schools and receiving some $$$. Its really that simple.
Curious...if you balance those 20 holdback kids in that age group (ie, 2020) with 20 other kids that are absent from tryouts are held back for a younger age group (2021) making tryouts easier for the 80 non-holdback 2020 kids, is it a wash?