Translation of the text floating around:
Q: "In Fourze's world, Riders are considered as Urban Legends. What inspired this idea?"
T: This being Rider's 40th Anniversary, we would like to step onto a route that respects the development and aspects of the previous series. That said, we will be using different ideas compared to the Heisei 10th Anniversary series, Decade. Decade presented continuity problems which we will tackle in Fourze and future series.
Q: "What thoughts went into the concept of the Kamen Rider Club and their research into the past Riders?"
T: KRC's role is to investigate the existence and cause of the kaijins and to help people. To that end, they have gadgets and serve as Fourze's backup in his fights. Gentaro will be the only user of Fourze, and will meet past Riders in his battles.
Courtesy of /m/.