Just received this email as well. I purchased a lifetime membership during Black Friday a couple years back. They're quoting the following terms as justification:

> 14.2 Termination. If you violate any provision of these Terms, then your authorization to access the Service and these Terms automatically terminate. In addition, Pluralsight may, at its sole discretion, terminate these Terms or your account on the Service, or suspend or terminate your access to the Service, at any time for any reason or no reason, with or without notice, and without any liability to you arising from such termination. In the event there is no Subscription Service in effect, you may terminate your account and these Terms at any time by contacting customer service at support@pluralsight.com.

The email directs you to their chat for support and questions, which is currently offline (email went out 1 hour ago).