Non-experimental worlds become experimental after updating to 1.18.0.27 Beta

Summary:
When updating to 1.18.0.27 Beta, some non-experimental worlds become experimental.

Steps to Reproduce:

1. Download and import My World.mcworld in 1.18.0.27 Beta. This world was created and last loaded in 1.18.0.24 Beta and has never had any experimental toggles enabled.

Observed Results:
The text under the world name says "Creative - Experimental" and if you try to load the world, you will get the experimental warning message.

Expected Results:
Non-experimental worlds should not become experimental when updating to 1.18.0.27 Beta.