Unfortunately, this is not some cool new feature or game mode that would benefit certain players. This is actually an error that many Call of Duty players have spotted with the new Maxis Bundle; some players are invisible in matches. Strangely, the weapons don’t seem to have been affected.
Treyarch has definitely noticed this and confirmed that they will be “investigating & working on a new fix.” Charlie Intel tweeted earlier that “The Maxis operator only appears invisible for players in their POV. It’s not affecting gameplay or enemies.”
Then they followed this tweet with an update: “The Maxis invisible bug is currently only affecting the Zombies mode. In MP, players are experiencing an issue where the operator may appear Adler instead. A fix is coming ASAP, and a workaround is to equip the Operator via the Bundle locker.”