iCloud

Yes. Apple doesn't make unsolicited phone calls. If there was a problem you would be notified when attempting to log in, including when logging into this forum. Also see: Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support

If you get these calls the iCloud account has been compromised , sensibly these are scams see the article https://support.apple.com/en-us/HT204759