All their supported proposals is about reflection, attributes (ie decorators) and in this case fine grained GC management (disposable resources).
I know a lot of their code embraces ES6 classes and such. I wonder if they will put forth a new proposal for dependency injection next, at this rate.
All this is to say, I don’t know how I feel about it
I believe that additional capabilities squeezed out of javascript if programmers can utilize type information at runtime.
Yes, there is a new-ish proposal [1] which is motivated in large part by DI.
(Full disclosure: I'm on the committee and don't really like DI or this proposal. But we'll see how it goes.)
[1] https://github.com/tc39/proposal-class-method-parameter-deco...
DI hast no space in the Standard lib. It is Framework space. It belongs into react, svelte or Angular. But not into a standard lib.