As this camera is geared for hybrid content shooters who work in sports, and is priced in the pro body leagues, it will get the kind of uptake that such bodies attract.
For me, the tech in the A9 III would be very, very useful, although the financial investment to acquire an entirely new system is a big entry barrier, not to mention that what I currently use (Panasonic S5 and G9) is adequate for my present needs, but not optimal. The A9 III body alone will retail for AUD $10,500, which is less than a new M10 or M11 body, but way more than a Panasonic S5 II X. For the price of an A9 III, one could buy a Panasonic S5 II X brand new, plus a Sigma 14-28, 24-70, 85mm f1.5, Panasonic 70-200 f4 if good deals can be had or buying secondhand.
I hope that in another few years, global shutter tech will be available in the L mount ecosystem, preferably with a Panasonic S variant. Global shutter along with improved phase detection AF would make the Panasonic S line close to perfect for me. As I'm not in a hurry for optimal, I am happy with adequate and mostly satisfactory, haha.