I am going to try to put this in simple words to avoid this confusion-
1. You DON'T have to submit the IELTS score along with your initial application to Nova Scotia.
What used to happen before April 10th was that in order to prove your English proficiency, applicants would just send in a letter from whoever to prove their English skills. It was upto the Visa Officers discretion to either accept it or reject it. If it was accepted, good! if rejected, the Visa Officer would request other proofs or test scores to prove your language proficiency. Basically, you were given more than 1 opporunity to prove your language skills.
Now, after April 10th, if you send in a letter trying to prove your language skills and the Visa Officer accepts it and scores you on the basis of the letter, well and good! If he feels the written submission is not upto par, he can either give you a 0 or a full score depending on his discretion. If he gives you a 0 or less than what you expected/deserved, you WILL NOT get a second opportunity to prove your language proficiency, as compared to earlier. You will basically have to accept the scores given by the Visa Officer on the basis of a letter.
So, it is HIGHLY recommended that in order to prove your true skills, IELTS is a better and a safer option.