In my opinion you do not have to do anything if all you do is add the slip ons, but... if you ride hard and get into the upper rpms frequently, I would get some kind of fuel manager.
If you plan on going to a high flow air cleaner at some point, I would bite the bullet and get a fuel manager now. Of course I am happy with the way my Dyna runs right out of the box and don't ride it hard so my opinion doesn't count for much.
The stock control unit will adjust back to the stock air fuel ratio but I don't know if it could handle a high flow a/c. HD says it won't adjust but I think that is really to please EPA and to protect themselves if you do modify and something blows.