I assume your letter, at the the end of the second paragraph, said: "SSHRC will contact you if additional funds become available." My understanding is that it means we are on a waitlist; however, based on the information they provide us in the notice of decision, it's impossible to know where we are.
I tried contacting them to see if they would tell me my position and they refused.
They did tell me something puzzling, though. They said that the "selection committees often recommend a pool of candidates to whom funding cannot be offered due to program success rates."
What this suggests to me is that it might not be a simple numbers game, after all. If they are trying to meet certain metrics of distribution (across disciplines, across regions of Canada, across universities, across English and French languages, and between with attention to gender, visible minorities, and indigenous people.) I suspect that an application with a high enough score to be funded, might have been passed over if it didn't check enough of these boxes.