Once T42810 is fixed, it may be possible to use the "badge" classes attached to the individual interlanguage link to prioritise the "featured" pages in some way. The Wikidata feature should provide something like this: https://www.wikidata.org/wiki/Wikidata:Development_plan#Badges
We could have an ULS configuration variable, disabled by default, that could be set to <do something> with links containing <badge XX>; the setting could then be enabled on Wikimedia projects and be the same on all wikis as the list of allowed badges is defined centrally in the site configuration of the Wikibase Repo (Wikidata). Of course the setting would need to degrade gracefully when Wikibase Client is not installed.
Would still need some form of consensus to enable a specific configuration on Wikimedia though, it's not entirely obvious (that will be a separate bug if this feature is considered feasible code-side).
T66797: [Compact links] Collapsed language links should preserve <a>, <li> elements and attributes