Come patch 4.0 im leaveing

So if i go to acc. manager do all that needs be done there to stop wow. Do i loss my toons if say in a year or 2 i come back.Only reason I am asking is i really do not want to play a whole new game thats calling itself worldofwarcraft , that is what that patch starts a hole new game. I only been playing from patch 2.0 and there has been some changes but not the hole game has changed it got better well some parts did any way some not so much. But right now i could play worldofwarcraftt , TBC or wrath and most things are the same but not after the patch forget that