If you count honorifics (Mr, Ms,), then technically Mr. Mime would be the first one.

But yeah, they haven't really done the double name thing before. I like it though, it fits in with them expanding the Pokemon world. I think all the first four regions were relatively close together geographically, so they had similar naming schemes. The newer ones seem to be getting farther and farther away, so they would naturally have different cultures and naming schemes.