Update: Since Sony announced the major firmware updates for Sony a9 in early 2019. It seems that a9 Mark II will not coming until 2020.
The Sony a9 was released in early 2017, becomes one of the flagship professional cameras in the world. The Sony a9 is also one of the top rated mirrorless cameras from Sony. According to our source, Sony is already working on a9 Mark II, to replace currently a9.
Our source said there are several version of a9 Mark II prototypes in testing. The release date for Sony a9 II is in 2019. a9 II will have improved image sensor, and better high ISO range and speed. Stay tuned for more info.