When a village dweller dies, joins another village, or goes to the nether, it should be immediately removed from the village dwellers' list so that the village can breed or spawn a replacement. This works correctly when mobs are killed or moved “naturally.” However, in my test worlds, when killing or teleporting golems with command blocks, the iron golems are not being removed from the dwellers' list until their timestamp reaches 20 minutes after they are killed or moved to another village.

Steps to reproduce

1. Load Iron golem timestamp bug 1.mcworld. It contains a small village that can spawn iron golems on a platform. Command blocks mark golem spawns with gold blocks and then kill the golems.
2. Wait 25 minutes.
3. Load Iron golem timestamp bug 2.mcworld. It contains a small village that can spawn iron golems on a platform. Command blocks mark golem spawns with gold blocks and then teleport the golems up to another village 180 blocks above.
4. Wait 25 minutes.

Expected results

Each village spawns a golem about once every 35 seconds, so >40 in 25 minutes.

Observed results

Each village spawns a golem once every 20 minutes, so 1-2 in 25 minutes.

Note

Using MCCToolchest to view village data shows golems remaining in the spawn village dwellers' list until their ts (timestamp) values reach 24000 ticks. In the second test world, both villages show the golem as a dweller.