Honestly as you read through the proposal the immediate impression is "they're just describing TypeScript syntax", which is... fine, I think? But I do feel like it would be a considerably quicker process for Node to just add the ability to parse a TS file than it will be to go through this formal approval process.
The process is standardizing the ECMAScript language. It would make types (as comments) standard for all JS runtimes, not just Node. I don’t think the community at large wants more non-standard Node stuff, as that’s a frequent point of pain and complaint (see OP article as an example).
