I'm not sure if you're splitting hairs or not. I definitely thought this post would be about them finding open source alternatives to binary firmware, but if it doesn't interoperate with optional non-free software then it is not Open Source.
It seems to be comparable to debian, and that's as open source as it gets.
Yeah, it's a perfectly fine place to land. My objection is completely to claiming to be 100% open source when it isn't; if they'd just said 99% open source, or that everything they'd written was now open, then I wouldn't mind (or at least, I'd view it as unfortunate, but I wouldn't be upset with them).