As part of working on T370802: Add a link (Structured task): Release as "turned off" to English Wikipedia, I discovered that the refreshLinkRecommendations.php script does not run when Add Link is disabled via CommunityConfiguration. This is incorrect – the refreshing script is a part of the backend, and as long as the backend flag (GENewcomerTasksLinkRecommendationsEnabled) is enabled, the script should continue running (the CommunityConfiguration flag should affect the frontend only, not the backend). Doing so will enable us to enable Add Link silently, in a way that needs only a community Administrator to enable Add Link via CommunityConfiguration.
Since https://en.wikipedia.org/w/index.php?title=MediaWiki:GrowthExperimentsSuggestedEdits.json&diff=prev&oldid=1237412036, refreshLinkRecommendations.php results in the following at en.wikipedia:
[urbanecm@mwmaint1002 ~]$ mwscript extensions/GrowthExperiments/maintenance/refreshLinkRecommendations.php --wiki=enwiki --verbose 'link-recommendation' is not a link recommendation task type [urbanecm@mwmaint1002 ~]$
Interestingly, revalidateLinkRecommendations.php works just fine, even though Add Link is disabled via CommunityConfiguration, see T370802#10025055.