Steps to reproduce:
- Open a Wikipedia page, which uses some data from the connected or other entity, and click Edit source
- Wikidata entities used in this page are shown at the bottom of the page [OK]
- Click Show preview
- Expected: Wikidata entities used in this page are shown at the bottom of the page
- Actual: Wikidata entities used in this page are NOT shown [BUG]
Tested on enwiki and cswiki