2008 and newer are designed to have the cab pulled for a lot of engine and trans procedures, it's nothing to hassle a buyer about unless they're trying to scare you out of buying it, or trying to mislead you by implying that the the cost of the repairs added to the value of the truck. Repairs by a dealer before sale don't add value, they preserve it by keeping the truck running and in a condition where it can be sold. I'd only care about them repacing the pump if it was a repeat failure that showed on the Oasis or Carfax.