After Jesus fulfills a prophecy, we do not continue to await its fulfillment—completion changes the expectation

If the Messiah's birth in Bethlehem is a prophecy and Jesus fulfills it, no one continues to look for a future fulfillment of that prophecy. The same logic applies to Matthew 5:17—when the Law is fulfilled by Jesus, the question is not "do we keep waiting for fulfillment" but "what does this completion mean for us now?" The aftereffects of fulfillment are addressed in Acts and the Epistles, not in Matthew 5 itself.