It would be so wizards to decide that, for example, Amulet Bloom didn't need a banning until they changed the mulligan rule to make it better.
I don't follow close enough these days, but does Scry 1 really make a big enough difference to a single deck to get something in it banned? I mean, how does that work out?
~SE++
I think its less for combo like Amulet, but more for Storm based combo. In storm based combo, you really need a lot of resources to go off in a single turn. In the most basic sense, you need a lot of rituals and ways to chain them together. Because of this, mulligans can be very backbreaking. Allowing a scry 1 means you'll be able to figure out if that card on top is something you actually need. There is the "nut draw" scenario in which you know what your top card is and you can can trip, hold priority, and crack your LEDs into a kill. In a more common way, you'll be able to put the extra land you didn't need on the bottom or the redundant tutor/ritual/etc. The way combo decks work is that they aren't really playing Magic in a traditional sense with removal and creatures and draw spells. Scry 1 is definitely not "draw a card" in this scenario. But when you're trying to build powerful synergies that require specific cards, I think scry 1 tacked onto something can lead towards something fearsome.
I think it's reasonable that this doesn't really matter that much, but I'm afraid of what this could potential do for more powerful formats. Especially for decks that just need a little bit more consistency to succeed.