All that's needed is the string "Wikispecies" at MediaWiki:Wikibase-otherprojects-wikispecies in order for us to have sidebar links at WMF projects. Thanks.
Topic on Project:Support desk/Flow
This label is only needed in some wikis - it is not part of the MediaWiki software itself, right? In that case, this label in fact does not belong into the MediaWiki tarball. Instead, please have an admin create that page in the according wiki(s)!
I don't know really. See Beta_Features/Other_projects_sidebar#Link_texts for more information.
I have created a task for this and can look into it. I see Wikispecies link on https://en.wikipedia.org/wiki/Cat What page(s) are missing it?
The message is set in https://github.com/wikimedia/mediawiki-extensions-WikimediaMessages/blob/master/i18n/wikimedia/en.json#L183-L194