I have seen the same problem in multiplayer but, if you raise or lower your gear with the mouse and NOT with hotas buttons then others WILL see your gear move! And whats more they operate a lot quicker, gear up in about 5 seconds!
Also if you raise gear with mouse then lower with buttons players will see gear go up, but not see it come down!
Perhaps someone can try this and confirm....
However the cockpit doors do not some seem to animate on other players'
aircraft so this is still bugged perhaps....