Can pork develop trichinosis if it is left out of the refrigerator?

No. Trichinosis is a disease caused by ingesting the larva of Trichinella that have developed in muscle meat. The life cycle of the parasite has to include going through the digestive tract of the live animal. If there are no Trichinella larvae in the meat before it is left out of the fridge, there won't be any there any time later.