Your Headcanon is Valid
@mariaann
I'd also add that there are distinct distinctions between:
(1) Authors always intended X to be true
And
(2) Textual evidence that X is true w/ or w/o explicit authorial intent.
1 is not where biMarco has come from (as the authors have said - this is cool we support this but don't give us any credit for it).
Instead biMarco is from 2. Both 1 & 2 are valid to read which I say only because some are too married to 1 and deny 2 as valid. I know you know this but many don't.
Starting a new post because it’s off-topic, but I think this is a super-important point about fandom, and a super-important point specifically about queering characters who are not confirmed queer in a canon work. If Animorphs fans don’t push for Marco to be bi, then the world will assume a straight default for Marco. If Animorphs fans don’t trumpet a read of Tobias as trans, the world assumes a cis default for Tobias. Even though canon never says either way.
The authors are awesome; I believe them when they express both regret over the lack of canonically queer characters and joy that the fandom is queering the cast. BUT as @mariaann said, the authors’ approval is nice but not necessary.
There’s this interesting space, between curative fandom and transformational fandom, that I would describe as “why not?” fandom. For anyone unfamiliar: curative fandom is collecting details from the canon work and describing them in worshipful exactness. It’s creating a floor plan for the Blade Ship based on extensive rereadings of interior descriptions, or attempting to construct taxxon grammar from canon utterances alone. In curative fandom, Canon Is Lord. Transformational fandom is expanding on and changing the canon work, including through critiques of its shortcomings. It’s writing fan fiction that unkills your favorite dead character, or drawing the Animorphs as Avatar element-benders. In transformative fandom, The Author Is Dead.
However, that split is artificial. Most fans curate and transform. My own blog has both obsessively detailed charts of Tobias and Rachel’s entire romance, and fan fiction about Tobias dating Marco instead.
And one particularly awesome middle ground is “why not?” fandom, which takes the stance “there’s nothing in canon that contradicts me, and therefore my read is this.” It’s the fandom space that points out that J.K.R. never says in so many words that Harry and Hermione are white, so no one can stop fans from making them brown. It’s the “your favorite is X” posts explaining that we have no proof Obi-Wan isn’t trans, and therefore there’s nothing to prevent us headcanoning him that way. The “why not?” fandom acknowledges that we’re all here because we all love the same story, but allows fans to see themselves in characters after lifetimes of sparse or bad representation. It gets buy-in from both the canon worshipers and the canon rewriters, with the goal of getting trans Obi-Wan to be as integral to the fandom as Sith Lord Jar Jar.
I do this too, because it’s a great form of compromise. Tobias notices “Aria” spending an inordinate amount of time picking out dresses and looking in mirrors, and therefore ALLORAN IS GENDERFLUID AND YOU CAN’T STOP ME. U mad, bro? Point to the line where canon confirms Alloran as cis.
I’ve mostly been talking about queering characters of ambiguous canon gender/orientation because I’m a white bi enby looking to stay in my own lane. But a lot of that also applies to ethnicities, disabilities, and other identities that get represented badly or not spoken of at all in one’s favorite works of fiction. And I really like it, not in the least because it turns the “I’m not racist, I just have respect for the all-white canon work” argument back around on the people making those claims.