~Edit: The original issue of this topic was not an actual bug. I has been edited to reflect the actual issue.~
“allow uncategorized topics” message should specify that admin accounts will bypass this setting.
Otherwise it is confusing to users that inaccurate bug reports might be done.
In my case, it was one of our community manager that reported that they could create a category anywhere even after setting this config to true.
We have configured our Discourse so that uncategorized topics are not allowed.
The error message popup shows correctly:
However, the use can click “+ Create topic” and it creates the topic anyway.