This is not the first time Disney has fallen behind on a project...when that happens, they typically start working around the clock. At one point, Disneyland's Space Mountain was not expected to open til November of 2005. They worked hard and opened it in July. I would bet SSE will at least be open by Christmas. Construction delays are constantly exaggerated around here, and there are only a handful of cases where attractions actually opened behind schedule (and attractions like Test Track or MILF are special cases).
Removing an entire showscene is too stupid to be true...I could see them accidentally destroying the wrong animatronics, though, which would set them back a bit...but unless you are the Liberty Square Riverboat, you are usually safe from major delays.