Curves, sliders, cutters, and 2SFB will break less I presume, giving greater advantage to the hitter.
I would probably phrase it as reducing the pitcher’s advantage, but what you are saying is correct. I read a study–which I can’t find right now-the raised seams allow for more drag but a rotational rate that decreases more quickly. The flatter seam ball can be spun faster, but grabs less air due to decreased drag. I read somewhere else that a curveball rotates about 13 times from release to the mitt. Can anyone substantiate this?