Their resignation is already being discussed in another post here from yesterday: One Of The Rust Linux Kernel Maintainers Steps Down - Cites “Nontechnical Nonsense”
…but I think this LWN reporting (from back in June) deserves its own post as it makes it easier for those of us who are not kernel hackers to follow what is going on.
The tone which comes across in the video (linked from the other post I linked to in this post’s description) is unfortunately much less amicable than this article conveys.