A new device, with the number of SM-A430U was spotted on India's import tracking website Zauba. We can assume it is the new Galaxy A4.
Samsung's policy with numbers is usually really clear: the second-gen Galaxy A3 is A310F, Galaxy A5 is A510F, and Galaxy A7 is A710F.
Sadly, the specs weren't revealed, but at least we know the device is being produced.