> "Arrow functions" (lambdas) existed long before CoffeeScript
I think the question was about whether they existed in the JavaScript community.
I'm sure much of Typescripts great features are not completely novel nor unique—e.g. generics come from c# and Java—but it is responsible for bringing them to JavaScript.
If CoffeeScript didn't have arrow functions, I don't think ES6 would have had arrow functions.
CoffeeScript had this mix of language features I think any language aficionado could have picked up at the time. It was just crazily succesful, no doubt due to its flawless execution by Jeremy Ashkenas.
"Arrow functions" (lambdas) existed long before CoffeeScript. Arrows of varying types (usually => or ->) have been standard syntax for lambdas for easily decades. One of the language designers on the TS team was involved in a language that had lambdas a year before CoffeeScript came into existence. To call lambdas a CoffeeScript innovation is like calling actors an Elixir innovation.
On the subject of CoffeeScript inspiring ES, that is likely very true - at the very least it lit a fire under an extremely stale language. They carefully selected some very good ideas that worked well together and made a beautiful language with them. However impressive, beautiful language design is not innovation. Something like optional any is.