(o|o)†𝄗𝄘𝄗(V)o￥o(V)

In Albrecht's notes, from WITW he says:

I went among the denizens of the plague year like a savior, my hands filled with healing. To those who volunteered, I brought more than health. Their bodies were primed; it needed only the Helminth infusions, brought from my own time, to work the alchemy of transformation. They have become partial Warframes, still in possession of their free will, yet enhanced, Void-attuned, capable.

And we know the Drifter has at least read the requiems:

He's your guy. Refused Kuva, which allows them to be immortal. Didn't go for the fashionable long arm. None of it

Thus I think we can assume Drifter has also read the notes and fragments.

So during WITW, the technocyte virus was already present in 1999, and the people who were turned into protoframes were volunteers who had already been infected and were dying.

Then the hacked emails on the computer next to Aoi confirm that the Technocyte was started by large music labels wanting to create boyband clones in early 1998:

Date: Feb 1998 To: "Director" From: "Gregory V." "You've made incredible progress on the Technocyte Coda project in just a few short months."

Then in the ARG leading up to the release of the Hex, there were hints that the ORO group and Kinemantic corp were going to be big players in the start of the Techrot, but that can be something that neither Drifter nor the Hex know.

So going into The Hex quest, the Hex knows that the Technocyte was caused by HitMaker music, and the Drifter knows that Albrecht decided to go back to 1999 because the Technocyte was already there. But then, as you pointed out, all of the conversations with Lettie and the others assume that Albrecht himself is the reason that people are becoming infected.

The first hints of retcon are in the Temporal Archimedea voicelines:

Minerva: "So, Velasco, I got a question. Was the Techrot part of the original timeline or is this all Entrati's doing?"

Kaya: "I… I don't really know. The timeline is murky, and history doesn't really survive the loop.

But...we do know. The techrot was already here, because Albrecht went back in time to find it. The techrot was part of the HitMaker plot to clone boybands. The Hex know this. So why is it suddenly in question if it's not a retcon?

Anyways, in the Devil's Triad KIM convos it seems the Drifter, despite knowing that the Techrot was already in Höllvania when Albrecht got there, is telling people he was the one who infected the city. So it can only be a retcon, unless the Drifter is actively lying:

LyonRank3Convo6: "What was he scheming? Did he infect the city, like I hear tell that he did to Höllvania?"

And then in convo with Marie, one of the options is to completely disregard the notes as lies, even though there's no reason given that Albrecht would lie in his private journals and is actually pretty self-castigating all told.

MarieRank3Convo1: His notes tell a very obnoxiously self-flattering story of how he went to study conceptual embodiment and instead came away learning the value of fighting the Indifference.

The Principle[sic] Writer is not Rebb, it's Kathryn Kingsley, the dark romantasy author who was originally hired to only write some 1999 KIM convos. She's since been promoted to Principle[sic] Writer, according to her bluesky bio and interviews she's given.

The homophobia is not outright saying "I HATE F----TS SO MUCH" (though whomever is writing Grandmother Entrati really seems to want to call Loid some slurs) but it's in the way the narrative judging gay characters MUCH more harshly than it does straight (or straight-coded) characters for the same or worse actions, and the constant devaluing of the one gay relationship in the narrative.

Kaelli calling Loid and Albrecht's relationship "a hookup"

Dagath calling it "whooping it up with his manservant"

Roathe's idle lines hinting at his ability to be sexually violent and/or seduce Loid.

Devaluing Albrecht's emotions and responses because they're not considered "correct" or about the "correct" things (this is like bog-standard homophobia, and also intersects a lot with ableism) like reproducing with the Correct Woman.

Loid's good ending is him being physically threatened and bullied into doing something he didn't want to do.

Even Marie is not allowed to maintain her affection for Albrecht: her good ending is that she must see what a silly stupid child she is for liking someone who treated her kindly and gave her what she considers a gift. (Again, with the ableism intersections.) The story doesn't think that she should be allowed to have her own opinion of Albrecht, the Drifter has to make her agree that Albrecht sucks, or at best, "is complicated".

When the Hex slag Albrecht off (Ex: Aoi calling him "devourer of worlds") you never get to push back. It's presented as just fine by the narrative.

The above is contrasted by how the current narrative treats heterosexual relationships and terrible people:

Arthur and Aoi's relationship was fraternization between an officer and an enlisted. This is never ever brought up in any terms approaching "whooping it up" or "hooking up" or "workplace romance" like Albrecht's relationship with Loid is. It's treated seriously. Albrecht and Loid's is treated like a joke.

In the DT KIM, where Albrecht is treated as a villain for being indifferent towards his forced marriage, Ballas is treated like this morally gray ambiguously tragic figure for murdering Margulis because she did not reciprocate his love enough for him in a way he approved of.

Mother Entrati (and Kaelli) were physically abusive to Father Entrati...but it is treated as a good thing that they are working together now, as a family. We have no indication Albrecht was ever physically violent with Loid...indeed, he laughs when Wally tries to pantomime him harming Loid. But now we're supposed to act like Albrecht was the worst person we've ever met to be in a relationship with? And assume that all of the relationship problems of other members of the family are on his head?

Roathe gets to just declare himself a good boy after being a genociding warlord on Tau, and the KIM ends, and he still uses the same horrible idle lines towards Drifter and is garbage to Loid. He never revisits any of his previous evaluations of Ballas and Margulis, or Albrecht and his relationships.

tl;dr: The homophobia isn't overt or obvious. I doubt the writers think of themselves as writing a homophobic narrative, because this is kind of the cultural cesspit of racism/sexism/ableism/homophobia/transphobia/etc in which we all swim. It takes a concerted effort to not reinforce these cultural bigotries in writing. But when you start looking at which relationships and characters are given grace and understanding and value in the writing, and which aren't...a pattern starts to emerge. And it's not a good one, no matter how much rainbow paint DE slathers over it every June.