I think a few of us talked about this around the time the new tackle laws were announced. Very few concussions are the result of high tackles and lowering the tackle height would have very little effect on the amount of recorded concussions. Some of us went as far to say that by lowering the tackle height, it might actually increase the number of concussions like we have seen in RU. I remember the RFL video that came out and it was funny they used an example of lowering tackle height and it was such bad technique in the video that if players were to tackle like that on a regular basis we could see concussions doube.
I believe they were just actively showing that they were trying to reduce concussions for insurance purposes, the small amount of data that they used to reach their conclussions backed this up in my opinion.