This page is confusing because it describes itself as ECMAScript 2018 but the features it lists are those I've associated with ECMAScript 2017.
Looking at the Github repo, you can see that they changed it from 2017 to 2018 on March 31st: https://github.com/tc39/ecma262/commit/8340bf9a8427ea81bb0d1...
So what happened to 2017?