Is this 'Cloud Subscription Terminated' message a scam?

Yes, it's a scam.

You can always check your iCloud storage usage yourself.

Check your iCloud storage on any device - Apple Support

1. That message never mentioned you by name.
2. There is no such service from Apple called "Cloud" (the proper name is iCloud).
3. That (edited out) phone number or email address directs you to a scammer who is (most likely) working in an organized scam call center in another country.

That’s all the evidence you need to block, report and delete the message.

If you receive a suspicious email or SMS text message that looks like it's supposed to be from Apple, please email it to reportphishing@apple.com. 

Learn how to ⇢ Recognize and avoid phishing messages, phony support calls, and other scams.

Good luck! 👋🏼😉

I get those all the time. It's a scam.