I've noticed after 200 days or so penguins stopped spawning during winter. Im now over 800 days and have not seen any penguins or any signs of them.
Also have not had any treeguards spawn in the last 100 days or so. I can cut trees down for days and not have to worry about them spawning
Seems the older the world gets...the more that breaks. I should note this particular world was created when dst was first released on PS4
I do not have any steps to re-create this.