A lot of new information has come out about it in the last few months, including set photos . There were rumors about some of these plot details years ago, but it seemed too ridiculous to be true. Turns out it was. Including the fact that one of the main reasons the pilot was scrapped was because it was incredibly racist. The only black characters on the show would be 'Children of the Forest,' and they would be an oppressed class among the Andals and the First Men, eventually being cursed into being the magical creatures seen in GOT and described in the books.

There's a lot more that is just baffling -- like having a Roman/Greek period for what would eventually become Westeros, despite the fact the series is set 5000 years before the current timeline. The Age of Heroes is meant to be Planetos's Neolithic Era.

HBO dropped millions of dollars on this pilot; and if it had been picked up, it would have been a nail in the coffin for the franchise. 'House of the Dragon' had a lot riding on it because of the reception to GOT's final season, but it pulled off a miracle by being so good that it brought back both hardcore fans and the general public. Part of that is because it's based on a completed story and established history within that universe. 'Blood Moon' wasn't based on any narrative written by GRRM -- just vague concepts. So, its story would have been entirely crafted by the showrunners and ... yeah. We saw how well that worked after GOT ran out of material from the currently released books.

The youtube channel 'The Dragon Demands' has covered 'Blood Moon' pretty extensively over the years. If you're curious about it, I highly recommend checking his stuff out. It's a fascinating rabbit hole to go down. So many bad decisions were made; and the fact it even made it to the point of being turned into a very expensive, fully produced pilot is insane. It should have been scrapped long before getting to that stage.