If you are cooking in advance on purpose to reheat at some future time there is no need to foil and hold if the butt was cooked to tender in the first place.
If the plan is to pull then fridge or freeze, one can leave the butt on the counter (on a cooling rack is helpful, over a pan to catch drippings) for the rest of 20-30 min, then pull the meat. It's best is cooled fairly quickly. Meat should not be packed warm into containers and fridged, nor should it simply be wrapped (unpulled) while still warm - especially if it has been handled.
If the butt is being held for later-that-day pulling and service it should not be allowed to fall below 130 for a significant period of time (using a tip-sensitive digital therm, not an analog bimetal). In most cases I suggest monitoring the surface of the meat during holding, not the interior as is commonly assumed. For intact meat cuts cooked well past the point of pasteurization (like butts), it is not the interior where one would expect pathogen growth, it is the surface where it was handled (breathed on, coughed on, possible exposed by sitting on a board that wasn't clean enough, etc.) that is more likely to experience outgrowth of pathogens, especially Staph. aureus.