The unit has the appearance of a moose (alces alces) which is also (but rarely) still called elk by British English speakers. The alces alces has flat-surfaced bowl like antlers, flat nose, and chin flap, just as depicted in the game.
The sound it makes however, is that of an elk (cervus canadensis) which is a large deer also known as wapiti found in North America. The wapiti has a pointy nose, thin pointy antlers with no flat surfaces, and no chin flap, unlike as depicted in the game.
Good catch, I had the feeling something isn’t right when I heard the animal’s in-game call the first time…
If even devs are confused by the animal’s names, maybe they should just have used the most common name in the English-speaking world today, moose. While the word was not used in Medieval Europe, they also use other terms and spellings that only appeared after the game’s timeframe (e.g. a donkey would have been called an “ass”, and nobody in the ancient world knew about a “juggernaut” ship).
Now that the elk/wapiti sounds are in the game, maybe they can introduce an appropriate unit, for additional deer variety, instead of removing them when proper moose sounds are added? Besides North America, Cervus canadensis subspecies also live in parts of Asia.