I find this hard to believe. The Coriolis effect has the most influence on global wind patterns and no one has suggested that the Earth was rotating in the opposite direction... yet. However, given all of the junk science out there presently I would not be surprised to hear that this will result from climate "change" too.
I note two things about this study.
1) The area where the winds were the reverse of today would have been near the southern margin of the ice sheet. I believe that the ice sheet would have generated a High pressure center over the ice sheet and the clockwise winds of the high pressure center would have been easterlies.
2)Changes in wind direction are not the only ways to alter water availability for trees.