Original vanilla ranked you and you needed to hit #1 or potentially #2 spot for the week vs everyone else to get that big enough push to make you rank 14 to overcome the rank decay that happens in the process.
I got up to Rank 11 without pushing it, but to go further required a dedicated push and it usually involved some negotiations with others also pushing for rank 14 so you didn't step on any toes. Once you get to 12/13, it's a very stressful grind, or at least it was.
I hope they do expand it but I guess that would be modifying the existing experience.