We just had a rule change for CL 11.
Old Rule
In the event of a substitution, the on-going games for the retired player will not be remade. Only games which have not been created will be allotted to the substitute. Both players will use up a slot playing this tournament. A substitution can be carried out by the CL staff. We will guarantee the substitution within a maximum of 3 days. Any new games created within this 3 day period for the retired player may be forfeit as well.
To this :
New Rule
In the event of a substitution, the on-going games for the retired player will not be remade. Only games which have not been created will be allotted to the substitute. Both players will use up a slot once the tournament has at least one game created. A substitution can be carried out by the CL staff. We will guarantee the substitution within a maximum of 3 days. Any new games created within this 3 day period for the retired player may be forfeit as well.
The full story can be found in the Division A thread. However, the short TL;DR version is that a clan (MH) did a sub that violated the old rule as it would place a player on 4 slots. However, this was not spotted in time and the tournament and games started. It was determined that the best action was to change the rule to what is now the new and current rule.