Normally, there are scenarios where topics are created, without being associated with any map or publication. Traditionally, these topics can be built in a tool like Oxygen. However, there is no way to edit these topics in Draft Space, and there is no apparent reason why this isn't and shouldn't be possible.
Ultimately, I see a major long term goal for Draft Space being to completely remove dependency on external tools like Oxygen and XMetal. I understand this may be a ways off still, but we should be moving in that direction, especially with obviously useful features like this one.
Similar idea for maps...