Some people here do expect dues to go up slightly now that the pool slide is open. That involves staffing lifeguards and carrying more insurance. However, given the number of points those costs are being distributed to, I don't think it will be huge.
OKWs dues trend has been higher than most of the other resorts - they've been historically cheaper, but their increases have been higher - at this rate in a mere 20 years or so they will be the most expensive resort dues wise! However, there really isn't enough history to say that with any statistical confidence at all. And when you are comparing SSR - no history at all.