Yes, this can happen. I wouldn’t say it’s a dangerous or a bad thing, since we often work in terms of a deck’s probability to show up rather than an absolute, binary “this will or will not show up.” We like to aim for the border, so that if we miss high or low we’re not too far off. The same goes for individual cards.

And sometimes, yes, a deck that was strong in early playtesting gets some nerfs in order to bring it in line with other strategies, and the nerfs end up causing it not to show up in the real world. One recent example was Temur in Theros-Khans standard. At one point Temur was one of the stronger clans, but we dinged Savage Knuckleblade and Temur Charm a little bit and it ended up just being a fringe deck in standard. (Though I will add it wasn’t too far below the rest of the metagame - people still played it in Grand Prix and in unified standard at the World Magic Cup.)

The only thing that would be dangerous is planning lots of other elements of standard relying on the fact that a certain deck is strong, not realizing we over-nerfed it. But that doesn’t really happen with the way we work, because part of our process is to avoid putting all our eggs into one basket.

-Ian