The titles for showing suggestions are in CX database. We query them for a user, source language, target language and list in CX dashboard. But the titles might be already present in target language - created using CX or any other article creation methods. CX Source selector and CX translation editor has checks and warnings about 'already existing title', so this check is not going to be missed. But even then showing an existing article as suggestion won't be good.
Following is the proposed strategy to keep our suggestion database updated