Since this update, the server replay system. There are always some players who are greyed out, and have mission location unknown under their names. I guess Gaijin did this on purpose to make us unable to spot cheaters anymore to hide the fact this game is still full of cheaters and they cant do anything about it.
Or is it just a bug ?
If you believe their is a bug with the replay system please submit a bug report thank you!
Link:Community Bug Reporting System