Possible natural spawning of a zombie horse in Survival singleplayer

Minecraft version: Java Edition 1.26.2

I found what appears to be a naturally spawned zombie horse in my Survival singleplayer world.

The world was on day 56, during the night. I was playing normally without mods, datapacks, cheats, or commands.

Before this happened, I defeated a raid using Bad Omen near a village. A few minutes later, I found a zombie horse near the village.

The zombie horse had no saddle. When it made a sound, the subtitles showed "Zombie Horse groans".

I attacked the zombie horse and it survived.

Steps to reproduce:

1. Play Minecraft Java Edition 1.26.2 in a Survival singleplayer world.

2. Defeat a raid using Bad Omen.

3. Wait near a village at night.

4. A zombie horse may appear.

Expected result:
Zombie horses should not naturally spawn in Survival.

Actual result:
A zombie horse appeared naturally in the world.