Did the Praetorian guard cease to exist after Caligula? or Nero? Nope
They will survive MoP and will have to be reorganised but the name will still stand imo
They are a tool of the Warchief Proud and Loyal and will do what ever the Warchief says thats there job.
If the Warchief says you will give out fluffy bunnies to orphans on childrens week the Kor'Kron will do it.
If the Warchief says liquidized some rebel trolls the Kor'Kron will do it.