Board Thread:General Discussion/@comment-35245590-20180407225057/@comment-16674955-20190509145244

It isn't litteral, it's a sort of teaser. It's put in perspective. So it's more like symbolism while at the same time representing what the next arc will be about. And I can clearly tell you that, if you had read arc 4, you'd realize how accurate it is. So nothing of that "trailer" is canon but it does represent the arc perfectly.