And I would answer, "If Grant Morrison hadn't referenced Freudian concepts in his interview, I for one probably wouldn't even have noticed that his evocation of that particular social transgression."
There have been a handful of of comics-serials in which the schemas of Freud are integral to the plot, as is the case with the 1987 MARSHAL LAW mini-series, and there are some in which the transgression plays a strong but more minor role, as is the case with Alan Moore's WATCHMEN. In 1234 the incest-transgression is more of a leitmotif.
Did something change between the time of Morrison's interview and the finished work? Did Marvel not want their fantastic franchise sullied, the way DC chose not to commission Alan Moore's 1987 TWILIGHT OF THE SUPERHEROES?
Probably not. At some point in his career Morrison began emphasizing themes diametrically opposed to the "grim and gritty" approach of the 1980s, with its marked emphasis upon reducing superheroes to psychological formulations (as indeed both MARSHAL LAW and WATCHMEN do). Despite Morrison's reference to Freud, he seems less concerned with putting heroes and villains on the couch than on the chess-board.
1234 (which is, incidentally, four issues, each loosely focused upon one of the FF-members), involves a great tourney between Reed Richards and his arch-foe Doctor Doom. This time, to counter the other three members of Richards' fantastic family, Doom brings in three allies of his own. Two of the three-- the Mole Man and the Sub-Mariner-- are, like Doom, the first major super-villains faced by the heroic quartet. The third ally is named "the Prime Mover." Morrison is vague on details, but it's apparently an alien machine, though Jae Lee models the Mover's appearance after an earlier "Prime Mover," a chess-playing robot created by Doom and drawn by Jim Steranko in a 1968 issue of STRANGE TALES. The Prime Mover gives Doom the ability to manipulate certain aspects of reality to Doom's liking, though Morrison also isn't clear about what the machine can and can't do.
So subtle are Doom's initial chess-moves that Ben, Sue and Johnny have no idea that they've been drawn into a mammoth game, even though it seems like another boring day around the Baxter Building, in which everyone's getting on each other's nerves. The exception is Reed, who has closeted himself in one of his labs with a "do not disturb" sign, and his absence exacerbates the irritation of his partners, particularly that of his wife, who gets a little sick of her husband disappearing to hunt down abstruse theories.
The reader doesn't learn until the last issue that Reed's self-isolation is a response to Doom's game, even as the villain starts picking off his enemies one by one-- which involves bringing in the Sub-Mariner to seduce Sue in her moment of weakness and to consign Johnny (and the Thing's girlfriend Alicia) to the subterranean world of the Mole Man. (Despite the cover of the third issue, the Sub-Mariner and the Torch never square off in an outright battle.) As for the Thing, this seems to be where the Prime Mover's talents prove most useful, in that the monstrous hero is not only changed into his human alter ego, but also reduced to his twenties and deprived of one of his arms.
Morrison's basic plot is largely indistinguishable from many similar FANTASTIC FOUR plots, but naturally the author infuses the characters with a mature sensibility foreign to the original Lee-Kirby comics. Morrison doesn't really get to the heart of Ben Grimm, and his Torch is also somewhat under-developed, despite a suggestive scene in which he deliberately provokes his sister after hearing of the alleged activities of the Sub-Mariner. But the writer does give full play to Sue Richards' feminine discontents, her healthy desire for the masculinity of Prince Namor, without compromising the reality of her abiding love for her husband.
And then there's Mister Fantastic, the group's "head honcho," a leader who manages to be at once authoritarian and self-effacing at turns. I won't detail the ways in which Reed Richards defeats Doctor Doom's gambit, though it's interesting that Reed must in part reject a "rewriting" of reality in which Doom becomes a sort of "evil shadow" to the hero. And not surprisingly, the four characters come together in their time-honored manner, re-affirming their unity despite all of their quarrelsome differences.
So, if 1234 isn't really about the displacement of hidden erotic feelings, what is it about?
In his 1944 play NO EXIT, Jean-Paul Sartre wrote one of his most famous lines, "Hell is other people." Later Sartre claimed that he did not intend this to be a general principle; it was a specific judgment of the characters in the play. But for all the fractiousness of the Fantastic Four-- who initiated the trope of "quarreling superheroes"-- it's clear that in Morrison as in Lee and Kirby, "hell is no other people."
And this is the final fate of Doom in the mini-series, who suffers an ignominious scolding from Sue Richards, who calls him to his face a "stupid, lonely, ignorant man." This is simply a more adult reading of the essential conflict between Doom, the self-made tyrant, and his four enemies. In FF#17, Doom confesses to his mirror that "I have never fully understood other human beings," contrasting his obsessed status with the Thing's ability to find love with another individual. Here, Morrison focuses more upon Doom's inability to love, which lines up with his reductive, close-to-Freudian view of humanity:
All men, even the noblest, are driven by the same base impulses. The sweet smile of the peace activist hides his raging need to make war on the makers of war. Behind every "selfless" act, behind every act of so-called heroism, there lies the craving for validation and status in the eyes of others. Is it only the lessons of our experience that makes monsters of us, or saints?
Doom asks this question of his Prime Mover, and Doom believes that he already knows the answer, that he can change the noble natures of his foes by manipulating "experience itself." And when he's proven wrong, he remains alone in his Satanic solitude, unable to anneal his suffering through the consolation of other fellow humans.