I would hope that if an author knew about a fanfic and had canon content coming up that was similar for whatever reason, that they would at least nod to the fanfic artist—acknowledge the fan that accurately guessed a spoiler. Or if they actually used a fanfic to inspire a piece of the same canon, yeah! Be involved with that writer! Get their permission and acknowledge their co-authorship for that bit! I just like to imagine authors and fans having fun together and supporting each other. XD It's my happy place. XDI'd imagine most fanfic authors would be overjoyed to have elements of their work show up in canon. Though it's probably a good idea to ask for permission first, just to avoid the possibility of starting shit with people.