Um, no. Leaving a band because you don't feel the music it is making anymore is integrity. Standing by and not putting your heart into the music is what the kids call "selling out" and it produces shit music.
I really want to see her sing this album. I get the feeling I'm not going to like the album, especially if it continues the homogenized path AM! has been taking, but I'd love to see the raw emotion I'm sure these songs will bring out in her.