Layout builder content blocks missing in preview for unpublished nodes

Problem/Motivation

After transitioning our site to Drupal 10, we discovered our preview links were no longer showing any layout builder node content blocks.

Steps to reproduce

View a preview link created against an unpublished node that uses a layout builder layout. Witness the missing fields.

Proposed resolution

Remaining tasks

Determine cause, patch, review.

User interface changes

API changes

Data model changes