What this does is it's going to change how prediction is going to work. Instead of "I think my opponent will send in a water type so I will use Thunderbolt in hopes of catching a Pokémon that may or may not exist on this team" to "Now is the perfect time for my opponent to send in his Vaporeon, so I will use Thunderbolt to hopefully hit it." You still don't know what moveset the other guy's Lucario is using until he actually sends it out. You still have to guess if Heatran is going to use Fire Blast or Explode on you.
Prediction is still there, it's just that everyone will now have more information to work off of. It will lead to great battles, just look at the battles on the Warstory archive where the two players knew the opposing team beforehand. Did knowing what the other guy have beforehand make for a less intense battle? Of course not. I'd even say those warstories have very high caliber prediction in them.
I am going to acknowledge that this isn't a completely positive change. There are teams that rely heavily on surprise factor and gimmicks to work, and this is a huge blow to them. Pokémon that have really only one good set will be disadvantaged. But hey, 4th Gen brought us new playstyles stuff that disadvantaged teams and certain Pokémon. (Nice to meet you, Stealth Rock. Yes, I always did want to know what it was like for a metagame to revolve around a single move.) Ideally, there should have been an option to turn this on or off, because giving people choice is always a good thing. But this isn't the big metagame killer that so many people are saying it is. But, like every generation shift, styles of play come and go, always have, always will. Circle of Pokémon, or whatever you want to call it.
And if you don't like it, DP will still be here.