However, I’ve never seen that distinction mentioned anywhere. After you mentioned it, I looked it up on my own and none of the search results I found mentioned that distinction.
What I did find was that at most they are merely examples of British English (hardback) vs American English (Hardcover), though that was only in one source, so take even that with a grain of salt.
Unless you have a reputable source to back up your claim, as far as I’m concerned, this is either dialectal differences at best or someone (not necessarily you) making up a distinction merely to feel superior to others at worst.