Australia thinks the D is ok. It ordered $1.2B...450 of them in 2016
Australia to Buy 450 Advanced US-Made Air-to-Air Missiles
The U.S. State Department has cleared a sale of advanced air-to-air missiles to Australia.thediplomat.com
Considering the D entered service in 2014, it was the most cutting edge American missile in service at the time. It was natural for Australia to go for it. Then came the PL-15, followed by the Meteor, after which Derby ER attained IOC and now there's the R-77M.
The D was significantly outclassed by the Chinese in just 2 years, in 2016, which is why the development of AIM-260 began in 2017. Raytheon's new competing missile must be a cheap upgrade over the D.
Very likely to be what was tested, but called D, the second missile.