Same has happened to me! I was in the team “Tootsies” — ranked somewhere around 50 globally. I noticed that the team leader was changing the minimum score to a higher amount as soon as she hit it, and the person with the lowest score was gone right after.
She denied booting people. Which was obviously a lie, since she booted me today! Even though I had a higher score then a few.
I find the kicking of people in order to get a higher ranking distasteful.