The lowest team fielding percentage in MLB so far in 2018 is .979. And just about every big league hitter has the juice to get out of the yard if they elevate more. It makes a lot of sense why this change is happening.
At the high school level. Your hitters with lower exit velo (below 85 MPH static) should be at 10-20 aLA. At that LA the ball is out of the infield, giving them their best chance at extra bases, which drives run production more than groundball singles/forced errors. Your higher exit velo guys should around 20-30 degree aLA - doubles and home runs.
Do hitters need to see these numbers all the time? No, don't become a slave to the data. As a player you still have to develop feel. Votto said it best, let the ball be your feedback. Coaches should be looking at those numbers, if available, as often as possible. It will help guide their approach to different hitters. "Hey Nick, I've noticed the past couple of days in the cage your aLA is a bit higher than what we'd like it to be, what have you been focusing on? Lets get some film today and think about driving the ball a bit lower and take a look" ---that type of engagement with today's player is HUGELY impactful. Couple that batted ball data with swing metrics using something like Blast or Zepp? Now you're cooking with gas. "Hey Nick, I've noticed the past couple of days in the cage your aLA is a bit higher than what we'd like it to be. Also your attack angle is getting up there, lets grab some film today and take a look, you may be losing your barrel somewhere or lifting too much through contact. Remember, you're not a high EV guy, these balls you're hitting at 30 degrees won't play for you the same way they will for our big guys"
The screens showed here at Iowa are phenomenal visual aides for players.