And this all goes to the fact that Gust (or better said, Tsuchiya) designed Ra Ciela's setting in a way different of that seen in Ar Ciel: in Ar Ciel, only Terus, Reyvateils and Moon Chanters could use magic (with the Reyvateils having access to the greatest power). However, in Ra Ciela, anyone can use magic as long as they have a pact with a Genom or have access to a functional Ciel notron, which is basically a device that emulates a Genom. And this is without mentioning the people that were modified to become "Doll-type Genoms", which can use magic without any outside support.
Similarly, Diving is possible in men and women alike, as Genometrics doesn't work in the same way as the Cosmospheres did in Ar tonelico setting-wise. However, I have to say that there won't be a song sung by a man in this game due to the artist line-up being already revealed and not including any male singers in it.