I believe that K1 shrinking is happening because algorithm doesnt know how to handle rating difference within the Top 1-10 K1 players.
They likely dont want the upper skill rating range to grow infinitely, but because top 1 player keep winning more than loosing. (If you check the ladder there is currently the 266 points difference between 1st and 11th place) Then his rating only grows, making higher difference between him and K1 lowest number bracket.
And if i am correct and they dont want the highest skill rating to be above some number so, they just keep removing that amount of points from all ppl forcing them to lower divisions because more and more space in K1 is just empty.
In the end if Top 1 will keep increasing his rating it has no solution except completely change the squish not by skill rating but by player numbers, but then the highest skill rating will just keep growing indefinitely as long as any player will always win more matches than he loose.
