Announced waaay back in June 2011, with the Alternity Dai Atlas and Goldbug (both of which came out later that year), the other two (Galvatron & Banzaitron) were assumed to be cancelled, because we hadn't heard anything more of them in the last 12 months.
Now though, it looks like they are back on for release in Japan, as an exclusive to Toy Hobby Market, for September (priced at 6,825yen - about AU$90).

Galvatron is a purple redeco of Megatron, while Banzaitron is a black redeco of Starscream (with green, orange and blue robot parts).