You know... I am not entirely sure, but I heard a story that says that Gensou Mangekyou videos that we see now are probably that we will see.
Because supposedly back during the SA video they did. They made some kind of announcement that they would no longer do Full fledge episodes due to the immense budget and time that was needed for the last one.
If this statement is true, then what we will be seeing is a music video. And music videos from here on out.
And thus we will never know why
Just saying don't hold your breath to think this will be another Fantasy Kalidoscope. But also I wouldn't be surprised if somehow and someway they find a way to get what they need done. (Maybe they should take lessons from Maikaze)