Good question - is this a formalization of the maintainership pilot, graduating it from its pilot phase to a proper working group?
Would some of the rules change? And would the existing rules be applied to all members equally now - for example, in regards to the requirement for maintainers to be core contributors?
Another practice that could be improved would be to assign all commit rights through the core contributor nomination & review mechanism, vs being automatic when joining specific organizations - this way everyone would have the same incentives to become maintainers: to be able to decide on what gets into the official code base (by doing the work of maintaining it afterwards).