The creature that died doesn't have to still be in its owner's graveyard to satisfy the activation restriction.
2022-09-09 • wotc
Similarly, Cult Conscript didn't need to be any specific zone at the time that creature died.
2022-09-09 • wotc
Creature tokens that die are put into your graveyard as normal (and cease to exist soon after). If a non-Skeleton creature token died this turn, it satisfies the activation restriction.