By separating concerns these first party modules could have their own release management and standards that suit that type of development. I think the problem Node always hits with the management of the core modules is releasing a runtime platform as a deliverable is very different to general purpose libraries.
First party modules could also be written according to strawman style proposals, or WhatWG inspired standardisation, so other developers could release competing libraries with different advantages.
I like the idea of an official module team that builds and release modules with a well-defined process. These modules would set the standard for other open source Node developers by having a standard set of templates for documentation, tests, automated testing/CI, etc, semver practices, etc. So if I invent the next great web server framework, I could get started by using one of the official Node library team’s modules as a baseline.