In my limited experience, the notion of "beginning, middle, and end" isn't so much a template or prescription as a way for writers to create a structure within their heads as they are developing a story. If writers don't have some sort of organizing principle in their heads as they write a story, the result is likely (not inevitably) going to fail to engage the reader (viewer).

In theory, an end-middle-beginning structure could work (depending on the story). What's important is that the story that the writer is telling has some sort of shape for the writer that can be transformed into a story that is compelling for the audience.