Some templates in some languages can auto-fill parameters from Wikidata. Examples:
- The Russian version of Infobox scientist auto-fills the birth date from Wikidata if the birth date parameter is not supplied.
- The Catalan version of Infobox building can auto-fill elevation and other parameters from Wikidata.
In both cases, if the parameter is explicitly written in the template, it is used instead of the Wikidata value.
The problem is that if the translator is being made from a language where the template is not Wikidata-aware to a language where it is, the user doesn't know whether the parameter will be auto-fill the parameter. It was reported to me already by one Hebrew Wikipedia editor and one Catalan Wikipedia editor.
It would be very useful to see this information while translating. In most cases the translator can skip filling this parameter and save time. It will also affect other article maintainers, so they wouldn't have to remove unnecessary parameters that override Wikidata values.
This is relevant for VisualEditor as well: The VE template editor should say that a parameter will be auto-filled if the user doesn't provide a value.
I'm not sure whether it's technically possible to do it at the moment. Maybe TemplateData can have a parameter property that says something "auto-filled from Wikibase"? Just an idea.