He is correct. That's the best way to retain the moisture, not overcook the meat.
Personally what I do is I pull the pork even if its purpose is to be future leftovers or "quick que." then I add family sized portions into a vac seal with some of their natural juices, and just take those bags from the freezer and toss em in some boiling water until they're DONEZO!
The Life of the Knife is Ended By! The Wife.