I got two info about a possible new Sony A77III A-mount camera:
Source 1:
the development for a77 mk3 is finished, it is now already in deep real-life testing cycle and it will be astonishing good and really, but really fast ;)
A SAR reader had a talk with a Sony manager who told him this:
Same A6500 sensor
Same A77m2 AF-phase detection module combined with a new Hybrid-AF (on sensor AF of the A6500)
4K Video
This all sounds very reasonable to me. Hope to get some more details about the announcement time soon. Anyway, A-mount is still alive for now :)