Definition of "fanwank"

Its just fanwank with no support in the lore - and not even good fanwank. As you said yourself, Malal does not exist in 40k - and he's never existed. And no, that's not a joke in the vein of 'I've never seen a stealth aircraft' either.

2017 April 19, Agammamon [username], “An interesting theory regarding Guilliman and Malal/Malice”, in Reddit‎, r/40kLore

Fan-producers seem to have integrated 'fanwank' into the new series, but not in a way that reproduces the show's 1980s history, or alienates non-fans.

2010, Matt Hills, Triumph of a Time Lord: Regenerating Doctor Who in the Twenty-first Century, page 61

What they favor is good old fanwank: continuity references, old monsters, and overcomplicated explanations of trivial plot details. If these are perceived as the voice of fandom, then catering to the fans means producing texts that the general audience would find at best boring, at worst impossible to watch.

2012, Leora Hadas, Limor Shifman, “Keeping the Elite Powerless: Fan-Producer Relations in the 'Nu Who' (and New YOU) Era”, in Critical Studies in Media Communication, Taylor & Francis, page 7

These episodes are full of subtle fanwank and the Doctor loves every minute of them, as evidenced by his beaming face and near squeals of glee when K-9 appears for the first time on Doctor Who since 1983.

2016, Melissa A. Click, Nettie Brock, “Marking the Line between Producers and Fans: Representations of Fannish-ness in Doctor Who and Sherlock”, in Lucy Bennett, Paul Booth, editors, Seeing Fans: Representations of Fandom in Media and Popular Culture, page 119

See above on Charlie's Angels. They never seemed to have lives of any sort and weren't interesting to me; they always seemed like soft porn for the guys, but a lot of girls fanwanked and fanficced them into more, so I guess they could qualify.

2005 March 9, [email protected], “Re: First Time Buffy Watcher”, in alt.tv.buffy-v-slayer‎ (Usenet)

She accepts, and tell Dwight that Philip was his son all along, but she needed to know he wanted to be with her for her, and just to have a child. Which completely contradicted the DNA test Dwight took at the end of last season, and is also just a crappy thing to do to someone. I almost started fanwanking the first time I saw this ("Maybe The Senator had the DNA tests switched?") before throwing my hands up.

2013 May 10, Michael Tedder, “The Office Recap: Second to Last Dance”, in Vulture‎

I cannot be fanwanked past the point that Chewie and Leia not acknowledging each other as he got off the Falcon was a fairly large mistake.

2016 January 11, AFK42 [username], “A possible explanation for why Leia hugs who she does at the end of TFA, regardless of potential familial relationships”, in Reddit‎, r/StarWars

Sherlockians term their light‐hearted conjectures the “Writings upon the Writings,” but the Great Game in some respects resembles the contemporary pan‐fandom practice of fanwanking.

2018, Roberta Pearson, “Janeites and Sherlockians: Literary Societies, Cultural Legitimacy, and Gender”, in Paul Booth, editor, A Companion to Fandom and Fan Studies, John Wiley & Sons, page 500