@Purodha: What is the use case behind this request which should outweigh cluttering the sidebar with more links that are not commonly used?

This is the exact same question everyone would have to ask about any interlanguage link. They are not commonly used, and they eat up screen pace which is unused in almost all of our skins.

If you are a multilingual or do cross wiki maintenance, e.g. spam hunting, or comparisons, or multilingual research, you want them. And you learn to hate that there is no easy way between language wikis for you, while all others have one.

This would resolve T102888: [Bug] Recent changes pages doesn't have anymore the interlingual wikilinks on the sidebar on some projects.

This might reasonably make use of Cognate, since the canonical name of each of the pages is identical in each wiki. It might need some knowledge that Special is internationalized to some other form and so would have to show interwikis on that page title.

Here is an example of a workaround:
In plwiki there is a list of some three dozen interwiki links on MediaWiki:Watchlist-summary in order to have them on Special:Watchlist.