Isn't that pointless ? They'd have enough time to report you, anyway..
It depends on which namefaker you use. (I'm not sure is there any in-game NF for Ghosts, tho)
Seems pointless indeed, but its kinda hard to force it to change it in game, never seen it for myself though. Also never seen one that does it in (mid) game. So far all namefakers change when the match is over and you're back in the lobby. Guess it was some private hack from some place idk?