I understand the search / duplicate issue. Ultimately, though, the title of a thread should be the decision of the poster of that thread. There is no need to be accuse posters of lacking permission to create their own titles.
The second sentence above gives me great pause in having any belief in the preceding one.
The accepted method is to post the original title intact, and if the poster so chooses, to add any additional text encased in ( ).
Nobody has "permission" to alter the original title of any article.