Apologies for the double post - but just found the source of "the renders are not final". It's from TailsChannel in a new video here. Also some guy on Reddit held an AMA claiming to have seen the movie at a test screening and leaked a tonne of stuff including story here. It's authenticity is still up in the air however. Beware of spoilers on that second link - though it could just be all made up and untrue.