I think it's an awesome thing. A lot of the themes between AI War and Valley 2 are similar anyway, though: desolation, humanity on the edge, a vastly stronger opponent that you are waging guerrilla warfare on, a hardy band of survivors being strategically led by you, and so on. Also, most of the AI War tracks were used in some of the high technology parts of the game, from the future regions where robots had taken over the world. I like to think of the two universes intersecting there anyhow, and now they musically intersect there as well, which helps even more.
EDIT: And I should clarify, the vast majority of AI War music would not be remotely appropriate for Valley 2 anyhow. It just has such a large library of music at this point that we could pull some really fitting stuff.