The proposal is missing any mention of third parties (users of our technology who themselves aren't part of the Wikimedia movement, for example various community platform providers running MediaWiki, or MediaWiki consultancy / development shops). This is a long-present shortcoming of our processes that I'd really like to see corrected.
Wikia/Fandom, for example, has a user and content base roughly comparable to Wikimedia, employ a significant number of MediaWiki developers and have their own MediaWiki-related technical projects. Omitting their expertise and representation from the process would be a mistake, I think. Similarly, the MediaWiki Stakeholders' Group (a user group mostly composed of people working in smallish MediaWiki shops) represents a user base that is often negatively and painfully affected by the technical decisions we make, because it is understood poorly by most Wikimedia developers.