Telephone call advising my iCloud had been breached.

Yes. Scam. Stay vigilant.

FYI: Apple will only call if it's requested by you.

Above is correct.

Even a call from a known phone number can be a scam, as calling telephone numbers can be and routinely are spoofed.

Here are some of the many scams around > Recognize and avoid phishing messages, phony support calls, and other scams - Apple Support