Pasting the relevant part for convenience:
Has anybody discussed the possibility of creating Wikidata items for extensions, after defining a set of properties to describe them? Linking those Wikidata items to
mediawiki.org extension pages, and then playing with templates and what not to keep the semantic data up to date (version number, last release, dependencies, compatible with MediaWiki releases...)? Then play with templates, queries and visualizations to create all kinds of useful output, from structured extension pages to a proper and robust map of extensions.