There is not an inherent reason why either one would be against code if done correctly. There are some things that tend to be done wrong when a remodel box is used after the cabinets are installed. There could be too many wires in the box for the size of most remodel boxes especially in the dishwasher/disposal box that may have more than one cable. Regular boxes in the wall usually have more cubic inches. There may also be a problem with properly securing the wire to the stud. A loose wire in the wall would have been a code exception on an initial remodel, but if this remodel is including drywall removal and/or repair, then the wires should be verified that they are secured properly, at which point it would be easiest for the electrician to put a standard box in the wall. There is often a code issue that arises with putting the box in the wall also. The electrician should be told how thick the cabinet back is so that they can install the box with the face sticking out from the wall the same amount as the cabinet back. They do make box extensions for this, but it seems that they forget to put them in when nobody is looking. It is also easier for the cabinet installer to cut the outlet hole in the cabinet before the cabinet is installed and the electrical box is already there, then it is to make the electrician crawl into the cabinet and cut the hole after the cabinets are installed. The only problem with putting the boxes into the wall first is that is seems that the cabinet installer's tape measures automatically read off by a half inch whenever they measure for a hole in the backs of the cabinets :D