Hoi,
What the RFC is about is actually quite simple. It states that the content of most of the lists and categories can be expressed as queries. So when an item is an instance of "Wikimedia list article" or "Wikimedia category page" it can be complemented by an "is a list of" property. For examples, [1] and [2]
The confusion is about something that turned up as a result; Wikipedia has lists where they expect Wikidata to treat them NOT as a list. Take for instance the info about "Wikimedia Deutschland" [3]. It is an "instance of" "list of Wikimedia chapters". This is patent nonsense. Obviously it is a "Wikimedia chapter".
The discussion is about should we maintain that is a "list" in Wikipedia as a list and consequently apply the property "is a Wikimedia list article" or should we make it an instance of whatever is applicable. In this case the German chapter is an instance of "Wikimedia chapter". All that it takes is having appropriate statements that reflect the function of the item.
As far as I am concerned, we only need both the subclass and the list when at least one Wikipedia has both. Where the other "lists" should live? Probably on the lowest level ie not on the list.
NB I do not consider what Wikidata will bring in query functionality. It does not exist so I consider what can be done now with WDQ. It escapes me why we need a special namespace for queries.I am however eager to learn more.
Thanks,
GerardM