In a motion offense, the low attacker will roll high and receive the ball where they can dodge going downhill towards the goal to shoot or feed to either of their teammates who occupy that low attack position in the rotation. I think the coach's comments are meant to convey that you should be comfortable making an offensive play, be it dodge and shoot or feed, from any spot around the goal.
Echo this, in many basic motion offenses the low attacker ends up high at some point. Many low attackers can't play high and thus are limited in what offense can be run. If your coach is running a true 43 motion or even a triangle motion, then the low attackers need to be able to play high.
