Wrong default preview item in theme editor

Short description of issue

Wrong default preview item in theme editor

Reproduction steps

Open the theme editor and go to the “Default product” template. There you’ll see that a default preview item is not a product but some collection not even present in my admin. Replicated in all theme trials in my store.

Additional info

Started after today’s theme editor UI update.

What type of topic is this

Bug report

Upload screenshot(s) of issue