Chitty – the idea that airlines cancel/combine flights at short notice just because of low loads is an ‘urban myth’ that crops up from time to time – they don’t, not least because if they did the CAA would get very ‘grumpy’!
Airlines do cancel/combine flights from time to time, but this is for operational reasons such as aircraft being unavailable for technical or weather related problems, or crew unavailability due sickness or going out of hours because of disruption, etc.