But this is front-end tech we're talking about, so who knows - maybe everyone will have to know PineappleScript in two years to do web dev. (Side note, I had to do a few googles to find a joke JS transpiled language that didn't actually exist - that should tell you how bad it is).
It was a weird language and deservedly died out
CoffeeScript only offered sugar and ways to avoid some of the quirks of JS, but the real problem is maintaining large projects written in dynamic languages.
Many of the features that made CoffeeScript fun and useful were incorporated directly into ES6. The proposals even cited CoffeeScript and borrowed the syntax verbatim or with minor changes. By the time arrow-functions were accepted it was obvious that the cost of transpiling wasn't worth it any more, all that was left was "significant whitespace", which was the most buggy part about CoffeeScript anyway!
I think CoffeeScript died because it didn't offer any real improvement, which TS offers even incrementally (in a single function, for example) without going all-in.