Unclear. They do absolutely refer to their gun as, say, the "MP5" in-game. Though, interestingly, in Modern Warfare (2019), many guns have two names; for examp

Unclear. They do absolutely refer to their gun as, say, the "MP5" in-game. Though, interestingly, in Modern Warfare (2019), many guns have two names; for example, the MP5 is also called SMG Charlie (as in, NATO phonetic alphabet for C). I kind of got the impression that it was laying groundwork for a long-term goal of removing the actual names of the guns; possibly due to licensing fees, or maybe to divorce the ugly reality of killing with video game killing, I don't know.