Canada is the party at fault, Microsoft is just responding to a stupid law.
Whats stupid about requiring people to opt-in?
Because this law (and any anti-spam law) is just like DRM...it only really affects honest people.
Large companies like Microsoft generally try not to "spam" you. Yes, you may technically receive an unwanted e-mail from them, but they do use some sort of opt-in right now. On the other had, true spammers don't care...they are just blasting e-mail to any e-mail address they can get their hands on. Then, when it comes time to enforce the law, only companies that are easy to find will actually be prosecuted...the fly-by-night spammers will never be bothered by this law, and if they are, it's likely they won't end up paying any penalties anyway, as their assets won't be as easy to find.
What this law does is make any company that wants to send you e-mail have to have opt-in plus confirm for every change of preferences, plus they will have to keep a lot more information about you, and this law seems to prohibit them from giving you a choice to receive "non-related" e-mail. Every e-mail under this law must fit a narrow category for which you opt-in. So, if you signed up for e-mail about "Windows 8.1", if MS releases "Windows 8.2", they cannot send you an e-mail in the "Windows 8.1" category that says "hey, Win 8.2 is out, it's great". This means that their categories will end up being broader, and this will inevitably result in more spam complaints about them, as they would "annoy" people by sending Windows 8 info on the "Windows" list, when all some people want is Windows 7 info.
A small business/website will be impacted even more. I recently got an update from a website that said they had partnered with a different company for their Android app, so the old app won't work anymore, and you'd have to download the new one separately. How in the world could I have opted-in to that e-mail before the fact, since blanket opt-in isn't permitted by this Canadian law. A few complaints from Canadian users, and this small site would have been bankrupted by the fines.
And, again, real spammers won't have to care about any of these issues, and you will still get phishing e-mail from "Expedited Shipping" about "Delivery Notification".