Youth players are defined under FFP rules by the age, not if they are academy or first team players. The money spent on players defined as youth players does not count toward FFP. When they are sold for profit, it counts positively toward a club’s FFP calculation.
The owners have said there is a separate budget for youth players. Buying all these 2004 born players is like printing free FFP credit for the future with no FFP counting against us. As soon as this is seen as Chelsea exploiting a loop hole, it will be screamed about in the press and they will start counting it when buying the kids.