They are a nice shortcut for the staff at Western. If you submitted an academic worksheet, then they already approved your courses (or not!) so they don't have to go through it again but rather just find the sheet in your file and you're good to go.
I suggest filing one of those ahead of time so there are no surprises! I submitted one and got approval for courses that they later gave me a hard time about. Fortunately, I was able to refer them back to that sheet and the approvals they gave me via email.