That doesn’t look like a one-time thing. It looks like all releases would have to be uploaded to this marketplace separately, which doesn’t seem like it’s worth the hassle.
Just an update.
I’ve sent a pull request to add some haxe related extensions repositories, and they were finally merged, built and included in the list, such as:
However, the list maintainers mentioned that they had to manually update one of the extension’s package.json in order to make it build, and they mentioned several extensions without a licence, which prevented them from being included. You can read about it in the discussion over the pull request: