The always reliable Ryan Snyder of Blue-White Illustrated had this to say on Twitter a little while ago:

There was no reason given for why this happened, but you all know my view on recruiting: Until signing day, nothing is concrete. Dioubate was a four-star recruit, but there are still four pretty good defensive linemen committed to the 2016 class — ends Shane Simmons, Michael Dwumfour and Daniel Joseph and tackle Ellison Jordan.

Penn State is down to 18 current verbal commitments in the class.