SonyAlphaRumors reports that it is getting more reports of an in-the-wild A9 III being tested in preparation for a Q1 2021 release. The Sony rumor environment is even a bit more echo-y than the Canon rumor mill, so sometimes a repeated rumor mentioned on a second site becomes “corroboration” on the first site, so skepticism is always warranted.
That said, the A9 II update that came in 2018 was notably light for a full number revision, which often sets expectations of a quicker-than-normal refresh for the next version. The rev II barely changed the sensor, but added new physical ergonomic improvements and doubled the frames per second on mechanical shutter. Despite having aged three years, the A9 still impresses with its fast sensor read out, now rivaled only by the recently released Canon R5.