Yes he has. And I'm pretty sure that every time he's said something like that, we've gotten something different/new for them. So I don't quite see what the problem is with him saying something he's said before. He says 12ki are awesome, he said that for 10ki and 11ki too. And MM singles are always "difficult" and "amazing" and S/mileage are often "new" and "improved" as well.
Can you imagine a proper ballad single by Berryz? That'd be awesome, but I don't think it'd sell too well. Now that'd be something new for Berryz, the closest is probably Kokuhaku no Funsui Hiroba.