There was a lot of speculation about Amazon's role in what happened, I'm not sure if any of it was true but worth noting.
My take is that someone on the Core team violated the Code of Conduct and refused to listen to the Moderation team, and the moderation team felt undermined and resigned in protest. But they were purposefully vague (probably so as not to burn any bridges).
It seems very likely that some of these changes in the Core team are related to that
I recall something about imposing Amazon corporate conventions on project governance, and people worried Amazon might start doing to Rust what Google has been doing to C++. As in that case, probably most of what Amazon wants for Rust, most other people want too, except for unlimited complexity. Corporations, by their nature, want things to be as complex as possible, regardless of what any individual -- even anyone who works there -- wants.
Can you elaborate on "what Google has been doing to C++"? Google has a couple of members on C++ working groups including WG21 but I'm not even remotely under the impression that C++ governance is controlled by Google.
Google has many more than a "couple of" employees participating in WG21 working groups. Most of what they do is helpful, but they are difficult to oppose.
I mean, their goals seem very understandable given the current abysmal status of C++ (with regards to insane language complexity, historical cruft, and ergonomic issues like compile times and build systems). My only skepticism is that the thing they want might be better achieved by making a fork of C++, since there are just too many things to rip out of and replace. (Ideally something which can easily interoperate with existing C++ code, but make some huge breaking changes that simplifies and streamlines the language).
I'm not that curious about the drama, but I wish we had more info about the governance of Rust and the vision of the remaining maintainers.
If these maintainers left on bad terms, what does that mean? Is their vision incomplete? Is Rust in good hands?