I'm not sure if this helps anyone, but it helped me.. I noticed today on Interfaces that you now have the option to hide empty Kanban Stacks. See my screenshot below - This for me solved my issue as my uncategorized column is empty! Don't know if it...
So I think I have a solution, at least for interfaces! I noticed today while doing more digging that you can select an option to "hide empty stacks" (See screenshot)Since my uncategorized does not have any records, it made it go away!!