Miles2Go2 said: "This may have already been discussed, but will Hadestown even be eligible for best original score since the music was mostly featured on Anais Mitchell’s 2010 album?"
It has been discussed, but I don't blame you for asking again. I participated in those discussions and I don't even remember when/in what thread those discussions took place. Anyway, I'll say basically what I've said before:
The score should be, and likely will be eligible because the stage show show has had a very long development period, which predates the concept album. According to Wikipedia (the most trustworthy of sources!) the album was made after workshops of the material had already been done. So the score was written for the show, but they recorded it as a concept album so the music could be preserved even though the album wasn't directly attached to an existing production. Shows like JCS and Evita also had concept albums prior to their onstage premieres, and both shows went on to get nominated or win Best Score
This is in contrast with a show like American Idiot; even though that album was written with a loose narrative in mind, and is sometimes referred to as a "concept album," the album was still an independent entity, which was only later taken and turned into a musical.