Checkboard,
Are you absolutely certain of that statement, if so, could you please provide a reference.
If that is what CASA is doing/allowing,
I wouldn't have the foggiest what CASA is doing, to be honest.
Conversion to ATPL at 1500 hours is what happens in Europe (but then, the pilot in command requirement here is covered by the FO's all logging ICUS on every sector they are PF. The company then provides a letter to the CAA which says "Yep - that's true hours, all right" - which gets around the requirement for the Captain to countersign each ICUS flight
)
As there is very little GA in Europe it's done that way because 90% of the pilots join with a bare CPL and 200 hours and never fly anything other than an airliner ever again. (i.e. they never gain actual Pilot in Command time, until they are in command of an airliner.)