Don't get this myself. They continually miss payments to players, staff etc. get a transfer embargo slapped on them, then it gets lifted just as the transfer window opens. Oh but they can only sign U21 players! What a punishment. It won't be long before they are missing payments again and what will they get, probably another transfer ban until the summer.
It allows them to replace high earners with younger players. Its a perfectly sensible approach if you ask me. Remember they can only replace outgoing players not add to the squad. It would be stupid to prevent a club with unsustainable running cost reduce them.