Feature summary
New topic tool should not allow adding sections without a header.
Use case(s):
There's no new section where you would not want to have a header for it. Currently the only reason this is allowed is to allow advanced users to use a template/copy-pasted header.
Benefits:
As of when I checked recent changes on enwiki, 448/500 new/unregistered users edits did not have a header in the edit summary. There's a few more edits that do still have header through a template like {{welcome}}, but to my estimation it is still the case that ~10% of new users are not using a header. All of these edits require someone to either add a header or revert the edit, so it would be good to stop these edits.