But for cunning brainlets like me? Its like having integrated into game save scumming. You don't really need what you do - just move blocks(items, units etc) around until you get good enough results(enemy bar red - preferable wiped and dead, your bar green and safe). Imagine playing x com but you actually get info if you hit or miss before you shoot or info about enemy reaction fire, all integrated into game. Just move here and you miss, but you can use other weapon and you hit, or move into different place. Of course you get better results if you actually know what you doing and use smart things like boosting speed of your cavalry lead units - so you can choose your battles and run around enemy, use orders and right compositions/skills/items, etc. But its really great help.
I definitely agree, and I reckon that this feature will actually be what allows the game to be playable by a wider range of people who typically would quite a game like this halfway through. While it's definitely on the easier side for people who already know how to play these games, I've watched quite a few people struggle pretty hard with many fights, simply because they waste precious time, do not understand many of the debuffs or actions, or do not set up their gambits properly.
I also agree that save-scumming would likely return, and since this is console only and has no "load" button, it'd be a pain in the ass to do and would turn off many people from playing, so I think that this is a bit of a "damned if you/damned if you don't" situation. Like you said, an optional setting for hiding predictions would be great for turbo-autists like myself, but I do feel that in the grand scheme of things this is the lesser evil. If the prediction-feature means that more people will play and promote the game, then that increases the likelihoo of more Vanillaware games in the future, and that's a good thing.