I would argue that the much bigger problem with the title is that it is generic. I do not mean generic as in, "it's plain and I don't like it" I mean that it is quite literally a generic descriptor instead of a specific one. Every expansion name has a specific proper noun associated with it. Not just "A Crusade of Fire" or "A burning crusade" a specifically named military campaign
named the
Burning Crusade; wrath of the tyrant named
the Lich King; the specific event named the
Cataclysm; mists of the continent named
Pandaria; warlords of the planet named
Draenor; the interdimensional invading armor named the
(Burning) Legion; battle for the planet named
Azeroth; the specific realm named the
Shadowlands.
But "Empire of Dragons" is non-specific. Like even as a reference to a specific hypothetical empire on the Dragon Isles within the expansion, it's not an empire of Dragons
named "Empire of Dragons", that would be insane. Also, you'd then presumably need a determiner, so the title would be "the Empire of Dragons", or it would need to be reversed into "Dragon Empire". Presumably the empire must have some other name, e.g. Dragonia, or Uldraconis or something. "Empire of Dragons" is just a general descriptor of what it is, but expansion titles aren't general descriptors, they have specific named references. Both because that makes them more memorable and because it's much better for copyrighting and trademarking purposes.
It's like naming the expansion "Realm of the Dead" instead of "Shadowlands".
Of course, there's always a first time. But it seems unlikely they'd break a now eight expansion straight trend.
It's most likely an artifact from whatever they originally assembled it from. It's not in all versions
