I agree. Something like Rust Language Foundation has both the clarity and gravity that it deserves. We will always have crates and components for fun names.
The "Ferrous Foundation" is appealingly alliterative. But it also makes it easier to expand the focus beyond Rust — which is probably a negative, because it makes it harder to concentrate on core competency.
Every foundation is engaged in a perpetual struggle over whether to expand its mission. But in the vast majority of cases, mission creep weakens the organization's ability to achieve its primary goals.
(Crafting a concise mission statement will help inoculate against mission creep, and should be done regardless.)