I get that it is a disappointment for some, but if they have to do alternate or even MIDI versions of the songs I think that would be cool as well. After all, there's a tradition of that in Pinball. I like how the artwork on the playfield is hand-drawn and the scenes from the movie have been "pinball-ified". There will also be altered images of the movie on the DMD as well. So if the music goes through the same process before it ends up in the game, I think that will also be cool.
I'm sure they will do a great job with it and ultimately you are getting more creative product because there will be new versions of the songs. After all, if you want to listen to the original songs, you can just download the soundtrack.