After the change in https://gerrit.wikimedia.org/r/531960 T230947: Support other ways to get the description of the page (which do not require Wikidata to be installed), a new configuration setting was added, that defaults to false (no description is fetched). Before that change, there was no configuration setting for that, and it was fetching the description from wikidata.

To continue using the description from wikidata on WMF wikis, the new configuration variable must be set:

$wgRelatedArticlesDescriptionSource = 'wikidata';

Impact

• This needs to be done before the affected patch (https://gerrit.wikimedia.org/r/531960) lands into production.
• There's no impact if the configuration is added before the patch lands in production (this configuration won't be used until the above patch is merged)
• If the patch is merged before the configuration change, descriptions will be missing from RelatedArticles until the configuration is changed.