As I get a bit older I appreciate things like this more so I'm not going to complain. I'd bet the reason they are doing this is because Yoshi has said he doesn't want ARR to be a game where you stare at the battle log for the entire fight, so this gives the players a good visual cue when something is about to happen. Could you do the same with more subtle mob animations of some kind to increase the difficulty? Sure, but this is probably a heck of a lot easier to pull off.