That early discussion really was focused on a "legal definition" which I don't think exists in the broad sense that people were trying to apply it. The phrase "immediate family" has varied "legal definitions" depending on the situation. Insurance, HR benefits departments, financial, government benefits, etc. but each defines that phrase for their own purposes -- and that definition as spelled out by that entity for that specific purpose becomes "legal definition." It doesn't mean it can be extended to any other company for any other purpose, without that new business officially defining it.
By removing that wording from the website, it would appear Disney has decided not to officially define "immediate family" but will likely work with individuals on a case-by-case basis. Which many posters were saying from the start.
Current processes actually allow more than 6 to be linked to a person's
DAS, but no more than 6 can be selected for a given Return Time. Substitute "4" for "6" in that sentence, and I suspect that is how it will be handled going forward.
Of course we don't know for certain until the change takes effect, but I do not think Disney is out to severely limit the experience of their park guests. They want happy guests, but need to find the balance. A simple change from 6 to 4, but handled pretty much as it is currently, would do that; with exceptions managed on a case-by-case basis.