After Sony officially announced a7 III (B&H/Adorama/Amazon), next cameras from Sony will most likely be Sony a7S III and Sony a6700. The announcement for Sony a7S III could be around Photokina 2018 in September, and announcement for Sony a6700 maybe in the second half of 2018. Stay tuned for more info.
In a recently interview with Sony manager Kenji Tanaka by dpreview at CP+ Show 2018 in Japan. He talks about recently announced full frame mirrorless camera Sony a7 III (B&H/Adorama/Amazon), and upcoming FE 400mm f/2.8 GM OSS Lens, a9, weather sealing, APS-C mirrorless cameras, firmware updates and more, you can see the detail below:
According to latest interview with Sony Senior General Manager of the Digital Imaging Business Group Kenji Tanaka by dpreview, he said that both Canon and Nikon is likely go full frame mirrorless within one year, before CP+ Show 2019 next year.