After perusing NFL.com I found an article about Robert Quinn and Chris Long. Apparently, Quinn has given them each a nickname and then a name for both of them together. It says nothing about a name for the D-Line or defense as a whole, but maybe this will lead to something.
Link: Quinn and Long
Sidenote: I assume Witherspoon is the backup for Laurinaitis if he gets injured and either Armstrong or Bates will fill in on the outside.