Of course Airlines (also MAS) want to have a full aircraft and MAS used to overbook their flights during the high seasons only. In order to get a full load it makes sense to overbook most of the flights hoping that there will be enough no shows, cancellations etc. Of course this doesn't work all the time and you nearly never get a full flight with no off-loads.
I only noticed that except in the high season the space control kept the availability always on the max capacity and they never sold one seat more than available, this happens normally 30 days before departure when all seat allotments have been given back to the airline and when they know how many seats they have left for sale.
Of course it also depends on the country/destinations where they fly from to KUL. Here in Switzerland people use to book their holidays just a few weeks before departure and so it makes logic not to overbook since most of them will be at the gate then.
Sorry, this hasn't to do a lot of BNE-AKL flights