What are some examples of non-canon material ending up being accepted as canon by the author?
Jorge Joestar.
Bardock appeared in the manga after the TV special.
On a similar note, Trunks going Super Saiyan upon Gohan's death has become so iconic that practically every version of that scene has used it.
>>160505429
Steel Ball Run was originally not part of JJBA but ended up being made the 7th part after some point.
>>160506122
The one thing I wonder about this, is in the original chapters, was Johnny not a Joestar or Gyro a Zeppeli? Because surely if they had those last names, it was always intended to later be marketed as Jojo.
>>160507580
They we're but Gyro was the main character and Johnny was his sidekick.
???
How is Level E an example of this?
>>160510794
I'm guessing because Ouji makes a cameo in the 2011 anime (the supposed manga "cameo" doesn't look like him at all). Also nen is mentioned once.