The main difference between UNIT_DISSIPATES/DIED/DESTROYED is mainly the english text that is displayed for people showing english-like combat logs. In all cases, the unit is considered destroyed and you can end processing data for that unit.
I'm guessing it could be used for units that despawn (say a leashed boss, or adds that despawn on a boss death)?
I'm guessing it could be used for units that despawn (say a leashed boss, or adds that despawn on a boss death)?