I had the same issue.. as I downloaded the form in April 2016(April 2nd 2016). I was checking the website every day just to make sure nothing is changed and on April 9th 2016 I noticed IMM 1344 is changed. So just to make things clear, I called CIC and the agent told me that it is best to send the updated form as they might ask you to provide an updated form. She also told me that usually they check the date when the application was sent and if a form was uploaded before that date, then there is a possibility that they will ask for updated form. Fortunately, I got the updated form within 4 days from my husband.
So my suggestion is to send the updated form to avoid the delays.
Thanks