That was pretty much my thought process, yeah. I knew A5e updated "Studded Leather" to "Leather Brigandine" which is what it -actually- is, and saw Hauberk and went "That's a chain shirt!" and left it at that.to be fair, a hauberk IS a chain shirt. a5e calling a full suit of mail "hauberk" is a misnomer, since a hauberk would only be one part of such a suit. so it's not an UNREASONABLE mistake to make...
Though, in fairness to EN Publishing: The chain shirt people imagine was never a thing. Hauberks were just maille and it's what everyone knew maille to be. The whole "T-Shirt Chain Shirt" thing is a pure Tolkien creation.