Common sense people.
If TUS decides to rule that you can play multiple PO's in same season, think about the consequences that are allowed.
If you lose a PO, your done, always have been, always should be.
An example that might take place if this is allowed: 2 man clan makes it to PO, they lose, then they join another clan that's already in PO and the clan lets them play = now they get to play PO's twice.. I can think of multiple scenarios that are equally ugly if this rule/behaviour is allowed.