> Coffeescript in particular, are good historical references to what will happen to TS in a few years.
The thing is that many good ideas of Coffee ended up being integrated in newer versions of JS, so of course the need for it decreased; one could argue that Coffee's legacy lives in ES201x.
Yeah, it would be great if TC39 made type hints syntactically valid but semantically ignored (ala Python's PEPs to that effect) so that type erasure was no longer needed as a "build step", but so far TC39 is still hugely aware of the controversies surrounding ES4 (the "lost" version of JS) and still very hesitant to do anything type related in JS.
The thing is that many good ideas of Coffee ended up being integrated in newer versions of JS, so of course the need for it decreased; one could argue that Coffee's legacy lives in ES201x.
But there are no types in JS, and none planned.