Sony has just registered a new camera code WW850128 in China. It has 5GHz Wi-Fi, and registered Sony WuXi, which means this camera may not be a high-end E-mount mirrorless camera. Maybe this is long awaited Sony RX10 V.
This WW850128 camera code should be announced in next 1-3 months. Currently Sony has a total of three unannounced camera codes: