WBREPONAME
Before "Wikidata" was replaced in messages with this variable it was possible to translate reponame in every message and use appropriate declension suffixes. How do I achieve the same outcome now using WBREPONAME?
You can't. You can choose to not replace with WBREPONAME and keep it wikidata.
Pikne, is WBREPONAME documented somewhere? Can you document siebrand's answer above in some place stable?
Not that I know. This could be documented at some WBREPONAME using message like MediaWiki:Wikibase-rc-wikibase-edit-title/en. But the solution confuses me a little and I'm not sure how to document this. As much as I understand the outcome of this message would be wrong if I keep it Wikidata and if someone actually ever uses it for some other repo than Wikidata (this should be the point of having the variable?). Though, I kept Wikidata for Estonian translations as suggested as this seems to be fine for Wikimedia.