Salam Yasamin,
I believe that is considered to be a good news. So, congrats.
I received the same letter. Based on an Indian forum discussion, I sent photocopy of the requested documents, the letter received from them, and I wrote a letter in addition to all that. In the letter I wrote that I have submitted these documents with my applications to Mississauga; however, I would like to send a copy of these documents to you as well. I submitted them through the link mentioned within their email.
In my opinion, it will not hurt you at all if you send them a copy of those documents and a letter to clear their mind, which might help instead.
Hope it helps.