yeah, know the flight path and you're golden.
the video is AC4, so the animations wont be exactly like FA, however the principles are the same. Horizontal dodges are ineffective vs mp0203, you might be able to avoid the brunt of the shot but more than likely you'll get grazed and lose a lot of energy in the process.
Look at 0203's firing pattern, its a broad horizontal spread missile. Going over/under is the way its done. More specifically, a perfect MP0203 dodge involves vertical thrust to get it to arc up from beneath you, cutting vertical thrust to avoid the missiles "back-swing" and likely repeating the process due to how quickly it reloads. Otherwise go straight to the ground, the barrage will shoot over your head, attempt to arc behind you and end up hitting the ground.