No what he said is the the RNC should force Cruz to stop criticizing his Donaldness or he would consider the RNC in violation of the pledge he signed. You don’t have to be an expert on reading between the lines to figure out that’s a threat. If he considers the pledge broken then there would be nothing to stop him from running 3rd party.
Oh, dear God - help us all. This isn’t what Trump said at all. Pay attention! Your comprehension skills are seriously lacking.