Sony has just announced the new a6400 (B&H Photo Video, Adorama, Amazon) APS-C mirrorless camera, it is now confirmed that previous registered camera code WW715296 (Registered on 11/02/2018) is the Sony a6400, you can see the above image.
So when will Sony a7000/a6700 and a7S III to be announced ? As there is no new Sony camera code registered yet, so we will not see any Sony camera announcement within 2 months. At Photokina 2018 in September, Sony already said that a7S III will take time, so we may see a7S III announced at NAB Show 2019 in April at the earliest. And high-end APS-C mirrorless camera a6700/a7000 could be announced the second half of 2019.