I'm nominating @MattiasBuelens. He has done quite a few critical fixes on our Web Streams implementation, always nice to work with and can help maintain a part of the code with few maintainers.
Commits authored on nodejs/node: github.com/nodejs/node/commits?author=MattiasBuelens
Pull requests opened: github.com/search?q=author:MattiasBuelens+org:nodejs&type=pullrequests
Issues opened: github.com/search?q=author:MattiasBuelens+org:nodejs&type=issues
Comments on pull requests and issues throughout the Node.js organization: https://github.com/search?q=commenter%3AMattiasBuelens+org%3Anodejs&type=pullrequests