Yep, very true (about the metals, that is). And I don't know about in reference to metal, but when referring to water, superheated means heated to beyond the boiling point but not actually boiling. As in, having liquid water that's more than 100 C or 212 F. (Supercooled is the same thing, liquid water below 0 C / 32 F). If that convention holds when dealing with solid metal, superheated solid metal would be hotter than it's melting point without actually melting. Which would definitely come after red hot, if it came at all.
My thinking is perhaps "superheated" was confused with phrases like "super heated" or "very heated", or perhaps the author just didn't know any better (I wouldn't have known better until a year ago myself).