When placed in a superflat water world, Enderman do not teleport or attempt to travel to a dry block when dying in water. 

The Bug

Enderman do not try to walk to a dry block when dying in water.

Reproduce

Create a superflat world and change the default top layer to "water"

Spawn an Enderman and put a block down.

Note how the Enderman would rather die than swim to safety.

Observed Result

Enderman would die rather than swim to safety

Expected Result

Enderman would swim a few blocks to save themselves.