What are the odds that yet another LGBT diaspora text wins again? I find it kind of hard to believe that this is the best writing this year when 6 of the last 10 Nobels have been LGBQ or ethnic diaspora adjacent.
2024: Han Kang -- no LGBT themes, characters, or plots
2023: Jon Fosse -- no LGBT themes, characters, or plots
2022: Annie Ernaux -- no LGBT themes, characters, or plots
2021: Abdulrazak Gurnah -- there are homoerotic themes in some of his work but the characters are not gay in terms of their identities, and homoeroticism has more to do with the ideas of power rather than sexual identities
2020: Louise Gluck -- no LGBT themes, characters, or plots
2019: Peter Handke -- no LGBT themes, characters, or plots
2018: Olga Tokarczuk -- I think her work is the one that fits your description best
2017: Kazuo Ishiguro -- no LGBT themes explicitely AFAIK, but queer readings of his work are a thing
2016: Bob Dylan -- no LGBT themes, characters, or plots
Gurnah is an immigrant (a refugee to be more precise) who can be considered living "in a diaspora" and his work does focus on the topic prominently. Ishiguro is a British citizen who thinks of himself as British, I believe, his parents moved when he was very young IIRC. He didn't visit Japan until his adulthood. I don't think his works are "disapora-adjecent" thematically but I only read two of his novels, so not completely confident here.
The rest write in their native languages and live in their birth countries.
I believe when you mention Carson's LGBT text, you refer to Autobiography of Red, it was written in the late 90s, not this year.
Edit: fixing typos, punctuation, and wording
Heavily anti-gay cultures (like Nazi and far right) produce surprising amounts of homoerotic art for some reason. I think it goes with certain kind of masculine supremacy - you need to convince boys they are better off with masculine boys only and somehow end up homoerotic as a result. Plus, I guess, once everybody is obviously not gay, people stop clocking those things as what they are.
Edit: not trying to imply that the book is like that, just want to support the point that homoerotic does not imply gay culture.
Ishiguro, Handke, Kang are known for their ethnic diaspora writings.
If you look at old Nobel Prize winners, you will find plenty of writers who are barely read now (at least in the English speaking world) and some like John Galsworthy whose reputation isn't what it used to be.