How did you remove it from File Explorer?
Maybe we were mistaken but it seemed to use that File Explorer had that as a hardcoded item now, since it's no longer in the registry, so we did the same in response to a bug report.
FWIW, if you want full control over what's in the New menus in Opus, you can remove them entirely and replace them with commands that create the file types you want, without any you don't want. On the default toolbars, the New Folder button-menu has an example that creates a text file.