I think, he is talking about football intelligence. The WRs are allowed to think about alternative routes if they recognize that their predetermined route won't deliver success for the team, i.e. recognizing coverage schemes and react to them or simply help their QB who tries to check down the ball but no one is behind the LOS.
Also a WR and any other player is allowed to think whom to block for their running teammate.
[ Edited by communist on Jan 30, 2014 at 1:02 PM ]