My own purely speculative view is that they fully planned to go ahead with Granato for one more year until Ruff was fired by New Jersey. When that happened Terry and Kevyn got together and it was "new plan". The rest is spin, optics, marketing, and PR BS.
I also think Ruff will get a say in personnel and other moves going forward. This will be his last coaching job and he will be bumped into a senior advisory role when it ends. The only question obviously is will it end successfully or not.