Board Thread:Questions and Answers/@comment-90.221.228.185-20150511233505/@comment-3250527-20150703060837

16.5 is regarded as fanfiction, despite the original author writing said fanfiction, is because it was listed on his Wordgear site under "Fanfiction" (or so the senior editors here say).

Right now, it's just really ambiguous in determining if 16.5 can be classified as canon, but even then, Kawahara insists on saying that 16.x Material Editions are not related to 16.5 in a any way.