Is this issue still valid? The link in the description refers to an edit that does not have any red highlighting at all, and lot of things have changed since NGS rc1.

It is, actually: http://test.musicbrainz.org/edit/17592932

On the linked page, this is because it's a table; the "Joka (German rapper)" is what's setting the width. Presumably that cell could be set to a colspan though, at the least. I'm attaching some files to show how reosarevok's linked page looks before and after adding colspan=2 to the top cell.

Looks like Add Artist edits just have the top row in a completely different table, so I'll just do that here.