ALL permanence is relative, due to entropy, as you tried to say. We still use the word permanent as a useful term.

Permanent, in the headline, is certainly meaning something like a ferrite magnet or ceramic magnet. "Permanent" meaning it does not naturally lose it's coercivity in any perceptually measurable way. This is different than saying a substance can't have the coercivity reduced.

> https://www.physlink.com/education/askexperts/ae472.cfm