EDIT: The particular thing that lead to me writing all this turned out to be a misunderstanding and it is all sorted now. I will however leave it up rather than delete all of this as it's still something I wrote and my stance on fan content vs stolen content still stands, even though what triggered this discussion is now sorted.
Fan content =/= stolen content. Legally they are similar but morally they are very different and the impact fan content has on the original content is generally very positive, by being what ultimately leads to someone watching / playing etc the original content.
Whether the fan content is an abridged series, a silly joke or meme, a series with animated characters from a cartoon playing video games (that one describes fan content that led to me joining a fandom and ultimately giving money to Hasbro when I bought comics from the show) or whatever it is, fan content is a love letter to the content it is based on and it's net impact is generally positive provided it's put in the appropriate places (ie don't put rule 34 fan content in the wrong place, especially if it's a children's show) and it ultimately tends to lead to the original content making money off of new fans who wouldn't have found it if it wasn't for the fan content.
Morally and impact wise, fan content, is not the same as stolen content. Stolen content is not changed in any meaningful way (ie only reason it would be changed would be to stop it being pinged by a system) and exists to replace watching content legitimately, which is a polar opposite to what fan content is all about.
The net consequences of piracy / stolen content can be positive or negative, especially when you add situations like "it doesn't exist in my country anyway" (like how Game of Thrones took forever to reach Australia, leading to mass piracy, for example) but the inherent morality behind uploading content with piracy in mind is world's away from the morality of making fan content. Stolen content and fan content are just simply, on a moral level, not even remotely the same thing and impact wise, fan content can only have a positive impact whereas stolen content can go either way.