Oz you can have up to 150 icus in your 250 cmd. No idea for NZ.
As long as you have have more than 100cmd from your flying school, that airline can give you icus before the upgrade.
From a practical standpoint, I would imagine that will only happen when they run out of pilots that fit GG's description with their thousands of hours.
Taking a guess on that last sentence so happy to be proven wrong.