I don't really see it as a deterrent, rather an attempt to force clubs to get their houses in order and stop this reliance upon sugar daddies (to some degree).
No, we burst through the ceiling and we are likely to do so again this season. But this ceiling is only put there by people that believe that paying top money guarantees success.
Well it will take effect from next December until such time as they can prove that they are no longer making a loss outside of the rules. So in this case, they have to turn a 55m loss into a 6m loss and then 5m the following season. So, it may be in effect for some time!