This doesn't mean it's open hardware or that it has open firmware. It has a closed source SoC and many other closed source components. Those components are closed source hardware with closed source firmware.

Snapdragon uses a fork of the open source EDK2 as their bootloader prior to the OS and publishes the source code. It doesn't mean Snapdragon is open source.

Most of the firmware has nothing to do with the boot chain leading up to the OS on the SoC.

That’s standard at a low level I believe. There are almost no open choices way down there, especially with modems.

Looks like they are doing what a small company is able to do.