I'm not claiming to know which answer is true, but from what I've heard, the slide at Coolidge Park is closed because the town is waiting for it to be insured. Part of the problem is that it wasn't built according to the specifications that were laid out in the beginning. I'm not sure why they didn't just make the contractor just rip it out and put it where it's supposed to be. But as I said, I don't really know a whole lot.
As for Reo Road playground. you probably already know why the center of the park is empty, but I'll refresh... When the contractors went to start the build on the planned center structure, they found that the fill of the playground wasn't suitable/stable enough for the intended play element. The cost of removing the lousy fill and replacing it with new would have eaten the entire budget for the park. So a simpler structure that can get the proper support will be going in. It looks to be the kind of thing that has a several climbing elements and a few slides. The color scheme is going to be "woodsy"—forest green and tan. And the sand table is currently off limits because it needs to have the sand removed and replaced with play sand.
But the parks are FANTASTIC! We've already clocked some twenty hours in the parks since they opened about a month ago. Our particular favorite is Coolidge's giant web climber. If you haven't seen them, check them out.