Surely it must mean that if you enter after it it counts for the next season... else why is that date mentioned? Teams'll just wait until their season's over... either midtable where -10 doesn't relegate them or do it when already down... I know it's not that simple but Leeds are showing that now if it is taken off this season. Perhaps they've had a bet with Bet24 that they'll finish 24th?
I think that is the idea of the rule mate - but it is just really badly drafted. I reckon that they should be able to get the 10 points deducted this season due to the way its been written.