If the Greek junta is defeated and the population believes that the US aided the Turks while Greece lost a chance for Enosis, the regime might be toppled by groups that would be friendlier with the Soviets. It's questionable if Moscow would straight up let them join the WP as the tensions with Turkey would mean there's a possibility of a world war breaking out over the Cyprus dispute.
It's similar with Turkey, though the Soviets might use their possible defeat in the war to further destabilise a powerful NATO member.