I haven't looked at the data itself, however here's some facts surrounding the whole D4 expansion thing:
On October 2 Blizzard
pushed the expansion to the encrypted fenrisdev endpoint. The key to access it was still available from a previous closed D4 preview and Blizzard forgot to regenerate it. People got to work on mining it (e.g. Stiven's "I can see what others cannot" tweet), but the files themselves are encrypted by various things too so it didn't "fully" leak, skip forward a bit and word leaks out, a YouTube video gets made and Blizzard
purges the CDN on the 17th and rerolls the encryption keys (Stiven also tweeted out an annoyed tweet at this happening

).
So up to that is real at least, I can't comment on the rest.