Are we certain that this IS progress?
According to the article, the chip is verified by using it with a FSF-approved distro. All this means is that no run-time loaded blob is required, it does not necessarily mean there is no closed firmware on the chip.
It could be that this is already sufficient for FSF, but I’m not sure.
Note that Purism’s desired purist standard surpasses RYF
Anyway, if they really created a free firmware for this, somebody should be able to point to the source. And in that case, it should be easy to at least also use it on the librem laptops, which also use Atheros 9k chips.