I enjoyed reading it, of course! It's really like an interesting little video essay, and well-written. I wouldn't have typed this long-winded reply if I hadn't liked it! I really love the "collective, unspoken roleplaying" aspect of emergent phenomenons like these "fandoms for stuff that doesn't exist" - just so many people pretending and being in on a joke. Something about it resonates with me. It's like the whole "brass kingdom" thing as well! It feels immersive, in a way, like opening the door to an alternate reality, and getting to live slices of the daily life like it is in that other world. It's a feeling like a change of scenery, exploring something new yet familiar, in a similar way to immersive experiences like videogames can provide (cultist simulator, potioncraft, monster hunter come to mind), some LARPs, or long-form, continuous, collective roleplaying experiences (to a much stronger degree I think). It's like there's this critical mass of immersion for a joke to turn into this little pocket universe that you can actually live in, even if it's just pretend, if enough people are in on it, it's undistinguishable from reality. (Sorry now I'm just musing.)
Of course, you were right to focus on it! It is a very fascinating topic! I'm looking forwards to your follow-ups!