Spin-orbit alignment around hot and cool stars

Mazeh et al. "Photometric Amplitude Distribution of Stellar Rotation of Kepler KOIs-Indication for Spin-Orbit Alignment of Cool Stars and High Obliquity for Hot Stars"
http://arxiv.org/abs/1501.01288

Study of the KOIs confirms the trend that cool stars tend to have aligned systems, and hot stars tend to be misaligned. Interestingly the alignment for cool stars appears to extend to orbital periods as long as 50 days, for which tidal re-alignment (probably the leading explanation for the alignment trend) would not be very effective.

Fascinating. So that would seem to be a strong argument against primordial misalignments and subsequent realignment being the norm.