I wouldn't feed raw pork because of the potential for trichinosis, which is a kind of worm that pigs can get.
I fully understand that not every raw pork specimen is going to be afflicted with the trichina worm; in fact, I fully understand that most raw pork specimens will not. But because the potential is there, I personally just would not feed this meat raw.
Because trichinosis 1) can be fatal, 2) is transmissable to humans, and 3) does NOT get eradicated by either standard worming meds or standard worming dosages either, I personally will never deviate from my position and would never feed any raw meat that might possibly contain this worm to my dogs. It simply is not worth the risk.
Regarding the prospect of freezing first, this is another reason why I avoid pork. If you google "trichinosis+frozen," you will also see this particular worm has a high resistance to freezing, which means you can't even get rid of this worm by freezing it. You MUST cook this meat to kill the worm. If you do a little research, the trichina worm is resistant to freezing because it is found in arctic animals (which live in the coldest areas of the world), and so this particular worm has evolved to be able to survive long-term freezing in the bodies of dead arctic animals, even when frozen solid. In other words, you "freezing" pork does NOTHING to protect either you or your dogs
Cooking solid will though ... which is why we humans ALWAYS cook pork 100% well done in our kitchens ...
Anyway, my own personal conclusion is there is no reason on earth to risk using "the unclean meat" of raw pork on your dogs, when there are better options.
Jack