The latter two novellas do tie into the main story in a couple ways, but only one is theoretically important..
Latest trailer. I’m very excited - the source material for this one is MUCH better than for the House of the Dragon.
The two GoT showrunners, David Benioff and Dan Weiss, had a plan back in 2017 or so to develop an alternate history show where the South won the Civil War. HBO was initially enthusiastic about the project, until people pointed out that having two white guys write a show where slavery is still a thing in the modern day was really not such a good idea.
That’s ridiculous, it would only be a problem if they portrayed it as a good thing. The Man In The Highscastle never had a problem.
There was a 2004 movie called C.S.A.: The Confederate States of America. It was a mockumentary that imagined a world in which the CSA had won the Civil War.
From what I’ve read, producers were extremely thoughtful with that show. They went so far as to carefully destroy every prop or other item with a swastika after filming. They didn’t want to be responsible for permanently creating anything physical that bore that iconography, that could then be misused.
I think that show is an example of how you can take subject matter like that, and handle it properly. Maybe HBO couldn’t figure it out, or they didn’t want to go through the effort, or they were afraid of political backlash after already going through this Game of Thrones incident: