Hi I am part of the Dance Fitness support team. Do to recent music laws we are unable to archive videos for a period of time. It is completely out of our control. The Hit classes we are using music that we can archive, but the dance classes we want to use the most popular music so because of that we cannot archive them for too long.
Once a video is no longer live it will take a little while for it to transcode, so you can watch it later. This is part of Vimeo and we have no way to speed that up. Sorry