I read through the newsletter you received and I can't seem to find where they state the issue was with the clutch disk specifically.
This is what I received in the email:
Here is a letter we sent out that explains what is going on with the JL clutch. I have looked at some of the forums and spoken to a few customers that have issues with their clutch. We did not do a recall on the clutch. If you are not comfortable having your clutch installed having read through the forums and the attached letter, you could return the clutch back to purchase point."