Change 518948 had a related patch set uploaded (by Awight; owner: Awight):
[mediawiki/extensions/FileImporter@master] Only show categories encouragement when empty

https://gerrit.wikimedia.org/r/518948

For testing:

• File without categories, https://en.wikipedia.org/wiki/File:NP225.jpg
• File with categories, http://dev.wiki/wiki/Special:ImportFile?clientUrl=https://en.wikipedia.org/wiki/File:Mari_Alkatiri.png

Add / remove categories by changing file info to see the information note appear and disappear.

Change 518948 merged by jenkins-bot:
[mediawiki/extensions/FileImporter@master] Only show categories encouragement when empty

https://gerrit.wikimedia.org/r/518948

I wonder if would be possible to still show this warning if all present categories are hidden categories? It seems that this warning message is mostly unused now since all files need to include some good template (a license) that usually has a hidden tracking category on Commons.

In T225693#5311131, @Pikne wrote:

I wonder if would be possible to still show this warning if all present categories are hidden categories? It seems that this warning message is mostly unused now since all files need to include some good template (a license) that usually has a hidden tracking category on Commons.

Hmmm true, I made this observation as well. - And I guess the idea would be having at least one non-hidden category then. - PM what do you think? @Lea_WMDE

I think this sounds like another ticket that should be estimated :) See T228992: Ask users to add a (non hidden) category, if there are only hidden ones