Ya, and? Hasn't AMD already let the cat out of the bag, so to speak, by having the Driver OpenSource for year(s) now?
AMD's 3D-supporting driver is not open source, so no. It's a blob. What they have done is release documentation for the vast majority of each GPU's inner workings, and then let a few of their people help the community devs out with the FOSS drivers.
But they have for Linux. I'm sure "sensitive", if there is such a thing, data can be gathered from that.
No more or less than on Windows/x86, or with Geforces. Their official driver is a blob. If they can easily recompile it for MIPS, it will still be a blob.
What they did was release hardware documentation, to enable others to work on drivers. With Geforces, Nouvaeu is having to clean-room reverse-engineer everything, and so their progress has, for various features, been limited and sporadic. Not that it's not impressive what they've done, but supporting them or relying on them makes no sense, from any major organization's view. With AMD, there is the option of using and improving the libre drivers.
MIPS open source drivers? I wasn't aware AMD supported MIPS at all. nVidia did for a while back when SGI was still in business(absolutely *NOT* open source), I can't recall ATi ever having support for Irix or any other MIPS platform.
Why would AMD need to directly support it[, at no additional cost]? The Chinese could pay coders very low wages to help improve the FOSS drivers, and come out cheaper [than paying AMD or NVidia employers developed world living wages for the work].