I think they’re saying that TS won’t add the feature until JS does. Still kind of a strange take IMO, but makes a little more sense.

First of all Typescript, is now more mainstream JS dialect than vanilla-js itself and, honestly, the only one i care about.

And i thought it's kind of obvious for anyone, that until *JS* proposals are staged far enough - Javascript won't have those features too. There is a good reason why TS waits for the stage 3.