I think it is possible and it makes sense. I think it was Franzese who said something else will come up like terrorism and the attention will go to that and the focus wont be on cosa nostra as much. this will give them freedom and allow them to build back up. but will it happen? time will tell.
what ur saying has already happened, after 9/11 the fbis main priority has been terrorism, and they have been steadily down sizing the amount of agents that invistigate the five families, i think its only down to two squads. and the mob has difinatly taken advantage of this but as evident of the "historic" january 2011 takedown, the fbi is only going to let the LCN grow so much before they close back in on them.