When Everest first opened the big yeti near the end of the ride would swoop her arm at the train. It was pretty amazing how they did it and it was a big arm. The swinging of that arm cause structural issues with the mountain so Disney turned it off and put a strobe light on her. Hence the nickname Disco Betti.
The OP was saying that Rivers of light was hyped up and supposed to open April 22 and now may or may not be opening this month, next month, this summer. Disney seems to build up all these AK events only to have them fail or break. Look at how long it took them to break ground for Avatar Land.
Changed April 222 to April 22! lol...that's a whole new calendar for me.