It was mentioned in the discussions around T105845 that it would be good to have more uses cases for componentizing templates; let's create a list here.
https://meta.wikimedia.org/wiki/Templates/Taxonomy .. not sure if @gpaumier has additional notes that might be useful.
Sorry I didn't follow up on this earlier. I don't have much more than the preliminary, exploratory work on that page. However, I think @Jdforrester-WMF does have some additional information about the different kinds of templates, which he meant to publish at some point.
This isn't directly related to the MediaWiki core component "MediaWiki-Templates", and I'm not sure what project or team would otherwise handle this.
For the moment, I'm closing this in favour of the related task T105845. Feel free to re-open if there's an action item here for a specific project or team.