If the dev would publicly say that they will be working on it again in the future, [abandoned] could be replaced by [onhold].
I think when it is an automatic function then I would prefer a different time frame / method :
SUGGESTION :
After 4 months unfinished without any update -> [abandoned]
[abandoned] can be one time manually set [onhold (until date)] for a timeframe not longer than 12months by a mod when there is a reaction to an automatic mail with information how long it will be onhold. When that timeframe is expired -> [abandoned]
And an additional function would be nice - that a dev can only have one game in development or onhold. Like a hint - concentrate on one game and finish it and don't start a new one until the first is finished.
There are enough dev that make a game alone as a hobby and 3months could be to pressed for time and there are enough situations in life where you have to push a hobby in the background for a longer time than 3 months. For example an accident like breaking your arm.