No they aren't. The nose of the airplane is still out front of the windscreen. Watching what the nose does lets you know what rudder is needed.
The example he used was rolling your wings and returning them. When we fight in this game we don't roll our wings and return them like this in a typical fight and as speed changes so does the amount of rudder needed to coordinate the exact same maneuver. In his example, the visual cue is your nose pointed at a mark on the horizon. In that case you could certainly see the yaw of the aircraft and could likely get good at a coordinated rolls.
Our 1v1 fights usually evolve into rolling scissors and as FLS said you are concentrating almost all of your attention on the other a/c. You are rolling inverted, back and constantly changing directions. The visual cue does not stay the same at all. Ever. There is almost no occasion to see yaw in your scenery and during the typical rolling scissors I encountered with better players, I have my rudder maxed out to one side or the other and never "see" the yaw if it is even evident because I am focused on the other guy.
Uncoordinated flight in AH is the norm in those types of fights so even if Katanaso changed his example to go to the TA and practice rolling scissors alone and learn to keep your a/c coordinated you would only learn to get your
a kicked. It's not the same. Even forgetting the angles advantage your opponent would get on you if you flew that way in a fight, coordination changes with speed and we don't do relaxed, smooth rolling scissors in fights.
Either that's not true or you fly into the ground a lot. 
Perhaps you should rethink that comment and consider seeing this occasion as an epiphany that revealed what you haven't learned yet.
I must be doing it wrong...my ball never stays center...never paid attention to it before...last time I flew I glanced at it....ya definitely not doing coordinated turns....
Nah, you got it right again.
Combat flying is based on the slashing attack and rough maneuvering. In combat flying,
fancy precision aerobatic work is really not of much use. Instead, it is the rough maneuver which succeeds.
— Colonel Erich 'Bubi' Hartmann Jagdgeschwader 52
Translated to "screw the ball."