Board Thread:New Features/@comment-32176272-20200320204605/@comment-1038387-20200320210739

From that blog:

The image chosen is generally the first image on the page that satisfies these criteria:
 * Larger than 130px by 115px for use on category pages, larger than 200px by 100px for the related pages module. Note: the size on the 'File:' page is what counts, not how it displays on the page.
 * Used 10 times or fewer in content namespaces on the wiki
 * One of the first 50 used on the page
 * Not an SVG

That doesn't sound like "randomized image selection" to me. I've seen it go right 999/1000 times. The only bug with it that comes to mind is Shared images.

You've got to work with the selection process and decorate your page accordingly. Game the system if you have to. Adding an image picker just creates more work as an editor. What are you doing that's out of the ordinary? Can you link to a category where you see a lot of mistakes?

It's unlikely that they'll be working on another custom feature, especially since pretty much all resources are sunk into UCP at the moment.