I haven't seen a thing about GDC internal assets before your answer - but, it doesn't mean that it isn't there. Mr. Joerg have (a little irritating, if you ask me) tendency to edit his posts much after anyone could have any reason to scroll back, so it's possible that you saw something that I didn't, just by reading it a little earlier. If you want to see and example of this is (just as a live sample of how communication problems arise in this very case) visible even in this very thread. My opening post have direct quote of Joerg's answer, and in his single post here, he quotes *the same* post with a little different content. Namely, the "GDC assets" bit is missing from my quote (because it wasn't there, back when he wrote it), but mysteriously appeared many hours later, in the middle of the night
Generally, the sole question of "why anyone would want to have schematics of 100% open device) seems strange to me.
Thus, I think that dropping any viable method of making Neo900 more widely recognized isn't helping. At least without trying, esp. if it doesn't cost anything (materially)
I still see some possible tensions - like, even in the Neo900 Team body, there seem to be different view on "if we should even try to release those project files at all, why anyone need them anyway", as opposed to "lets do everything to release as much as we can, and explain why we can't some things". You know, the inversion of roles - for some - like you - it's natural that if you don't release something in Open project, you explain why. For others (Mr. Joerg, as it seems from posts here) it's the other way around - people should explain why they want it and convince the releasing party.
Jörg always has been project leader. The Neo900 project only exists because he envisioned the idea brought together the people to make it possible. AIUI, Nikolaus has always supported this and the only problem is that the the project leader must make the financial relevant decisions which meant that Neo900 UG had to be set up.