Fact that anyone official commented on matter is big deal, but it's still worth nothing and change nothing. AMD for instance has proprietary firmware on GPU too and their highly technical Linux staff (John Bridgman and others) confirmed many times they simply can't open it even if they wanted to due to all DRM-related certification, agreements with IP partners, etc.

And it's much worse in case of PSP because first of all it's ARM IP and they wouldn't be able to change anything without agreement with them. Also after a little of Google-fu I find interesting document:

http://fileshare.arseniyshestakov.com/mirror/AMD_PSP_Briefin...

That's mirror, but you can easily find source. So AMD actually pitch it not just to governments, but also defence institutions and this is just much much worse than story with DRM.