There's no reason why the title would or should be changed by anyone other than the conversation creator.
There is reason if the conversation is started by normal member and the other recipient is admin.
The member creates a conversation with admin with this as title : "????".
Another member creates a conversation with admin with this as title : "HELP".
Now if admin receives > 50 conversations daily with meaningless conversation title, and the admin can't change the conversation title, it will be hard to know which conversations are important
