Not exactly. Google is using wasm where it makes sense to do so.
Google is heavily invested in TypeScript and JavaScript. Closure Compiler is far from half dead but the need to support current language features is mitigated by translating front ends (like TypeScript).
It will support these features eventually. Public field support is mostly there, just not on by default.
Actually no. You rarely need to annotate anything. They type checking is independent from the optimization of you turn off the type based optimizations. You still get good results. This doesn't get you away from the requirements for advanced optimizations (property use restrictions in particular).
In strict mode you can because you can statically determine if eval is present. If it isn't, it is trivial to determine if it is written to after initialization.
Otherwise it has the same issues as const (is there a temporal dead zone violation?)
Google is heavily invested in TypeScript and JavaScript. Closure Compiler is far from half dead but the need to support current language features is mitigated by translating front ends (like TypeScript).
It will support these features eventually. Public field support is mostly there, just not on by default.