Steps to reproduce

1. Seed 196916914
2. /tp -2222 222 -222
3. Set up a repeat, always active command block with /kill @e[type = !polar_bear]
4. Go down near the ground and look around.

Expected result

No polar bears.

Observed result

Polar bears spawn.

I Randomly Saw Polar Bear And Its Cub In The Snowy Slopes Mountain