Currently translations are published to the user namespace which requires unnecessary extra steps for users to move to the main namespace. From user tests, user expectations for "publish" seem to be for the content to really go live.

Publishing to the main namespace should not be problematic because:

• Users are creating new content, not replacing existing one, which generates less conflicts if reverting changes are needed.
• If content exist a warning and option to publish in user namespace will be provided according to T76180
• We already persist translations before they are published so that users can improve them and publish when those are ready (adding another intermediate state seems just to complicate the mental model)
• Users are registered which makes it a less favorable option to vandalism than regular editing.
• So far we got 0% reverted articles from those published using Content Translation.
• when testing with users, that is what they expect to happen when clicking "publish".

In our experience of releasing the tool initially configured to publish in the user namespace we found different issues:

• Users moving their translations to the wrong location (example).
• Users copying the content manually to the main namespace (example copied from here) which breaks the statistics and the possibility for the community to track content created with the tool. On January 26, I could find 19 articles moved manually in catalan Wikipedia.
• Users asking to remove their user namespace pages after moving the content to the main namespace (example) which produces additional work for admins.

More details at the Catalan Village pump discussion

After making publishing to the main namespace the default on Catalan Wikipedia (that is, making a tool that is supposed to create articles, to create articles once you press "publish"), we identified no issues.