Well it could be added (or listed if > 1), but I doubt it's usefulness. I think genre is a good way to filter albums, but once you have focused on an album I don't really see the value of showing it's genre : if I see a Metallica album I have a pretty good idea what genre it is, same for Bach. If it's just to visually confirm that the genre tags are correct you could go & edit the album's tracks.
Well where to show it for one thing, would you expect it to show all genres if there are multiple, or just the main genre? We may find room for the latter. Some compilations could have several to many genres remember.
I make it a point to tag stuff with a single genre for simplicity's sake so multiple genres is not a concern for me. As to the where, I guess you could put it in the upper left corner where the album name, artist and the album image is.
See if you like 1.5.41 - it had to go in the left panel rather than the header area. When there are multiple genres, it shows the main genre first (the genre on most tracks).
No I don't want it in the header, I don't want to juggle the other header data to make room. I have some pseudo-album compilations where there are dozens of genres (eg. Rolling Stone magazine's 500 Greatest Songs of All Time) and I suspect other users may have the same. The left panel, being scrollable, means this can be accommodated without issue. I think the genre(s) comes under the category of incidental data when looking at a single album, rather than key/header data.