I am not an air conditioning professional, but a few years back I did a fair bit of study on the subject.
The problem with any air conditioner, reverse cycle or otherwise, is that when the unit is switched off, especially over long periods, the refrigerant gas (as a liquid) tends to migrate either to the coldest location or the lowest location.
Think of it as boiling and condensing, where the fluid boils away from the hottest part of the system, and condenses at the coldest part of the system. If the temperatures are about equal, the liquid refrigerant will tend to accumulate (drain down) to the lowest place it can find.
What you don't want is for all the liquid gas to end up in the compressor, either the sump, or within the cylinders.
If it tries to start up under those conditions, one of several very bad things can happen. The motor can go into hydraulic lock and risks burning out if a fuse or circuit breaker fails to protect it, or more likely the reed flap valves in the cylinder head can be damaged or broken.
Many split systems that are installed with the compressor outside probably at ground level, in cold climates need some kind of sump heater to protect the compressor. If the compressor is roof mounted in a warmer climate, the problem is much less likely.
Any packaged system such as a window air-conditioner or domestic refrigerator or freezer does not suffer from this problem, as most of it will track ambient temperature pretty well when it is off. Its mainly an issue with split systems, especially in cold climates where the compressor is located well below the height of the inside unit.