I think spankalee meant NPM packages being distributed as ES6 modules rather than ES5 source files that use require() or are pre-bundled with something like Webpack or Rollup (as is the case for many frontend packages). Node.js has support for ES6 modules since version 8.5.0 [1], so this will slowly become feasible.
I will believe http2 can efficiently replace a module bundling step when I see it ... unless esm also magically replaces the small module mentality of the npm ecosystem there will remain a ridiculously large number of small packages in the module graph of apps using npm packages ... turning module import into an async operation without a bundler is going to require a ridiculous number of round trips ... somehow dynamically building the bundling mechanism into n*m server layers sounds like even more of a nightmare to me than webpack ...
Also — even if you make every module import async — why would you want to get rid of the ahead of time bundler? Walking the module graph ahead of time is enormously useful for static analysis ... it seems to me like asynchronously loading a module is a special case file size optimization not the normal usage of a module in a program ...
Do people really see mjs and http2 as removing the need for module bundlers? I ask because I’m honestly extremely concerned — I thought that javascript modules were eventually going to grow a new syntax for async module loading not turn every import into an async operation. I don’t understand the vision being pursued here ...
It means we don't need them at development time. Just use modules (and an http/2 dev server for better multiplexing), then do bundling and other optimizations only for production.
It also means that project like in the article can mostly just go away - you don't need a custom loader.
[1]: http://2ality.com/2017/09/native-esm-node.html