The release date on both IOS12 and WatchOS 5 is tomorrow. I rolled back from IOS12 beta to IOS 11.4x because I had some special challenges on my AW and they never showed up in my activity app. I wanted to make sure that I had them before going to IOS12. I know a number of people also reported this bug. One guy dropped back to 11.x and then back to 12 a few times to make sure it wasn't something he was doing. Every time he went to IOS 12 all his special challenges disappeared even though under 11.x they were all there. We will see tomorrow.