I mentioned this is in a different thread...but we really don't know enough to make a blanket statement that bullet spin pitches don't break.
It would be possible to throw a bullet spin pitch where the axis of rotation with the ball is different than the direction of the ball flight.
If that happens, then the seam orientation is not symmetrical. One side of the ball would have more drag than the other side of the ball, and the ball would break.
Here is a Rachel Garcia riseball:
This is clearly a bullet spin pitch. Yet, the batter swings 6 inches below the ball....suggesting that it was a riseball.
That's the spin!!!!! yes!