With any message like that that falls into a gray area, it's best to seek legal counsel. However, a safe rule of thumb to play by is that as long as the message is purely informational and contains no commercial information then the answer is no, they would not be commercial electronic messages.
The definition of commercial can differ, so we would certainly recommend following up with a lawyer. If you're not sure, don't send it until you are, and be sure that you are clear to your customers when they sign up for such notices or messages what they are signing up for, and remind them in the email. View our CASL page for more information on Canada’s Anti-Spam Legislation.
About this particular situation, no. SimplyCast can and does ensure that your messages include an unsubscribe link however, and a lot of the other steps in the CASL regulations are best practices anyway. If you ensure you handle the rest, we'll pop that unsubscribe link in and you'll be able to rest easier.