Yes, they did use them in spring training. I have a feeling they will be banned very quickly because these new bats are designed for the hitter's sweet spot. So the reason why they're cranking is because the barrel of the bat is now where they kept missing. So instead of rewarding the pitcher with an out on a poorly hit ball because he missed the pitch, the pitcher is now punished for making a good pitch because of a weird shaped bat. A weird shaped bat that now has 2 contours, so how will they try and explain the shape of the bat away?
They should be forced to make the head of the bat bigger to match the new shape of the bat, see how much heavier they get and if it's still worth it.