isDefunct

True when this match object is a corpse: cancelled at construction, or already evicted from instances. One-shot dungeon instances leave that registry the moment teardown begins but stay referenced by the dungeon browser for another 30–90 seconds while their world awaits deletion — and destroyMatch resets state to WAITING as part of teardown, so state alone cannot tell a fresh lobby from a dead instance. That ambiguity is how players ghost-joined dungeons that were being deleted and got stranded.