I never understood why music publishers care so much about licensing for old games. Are they worried people are going to put on GTA3 to avoid buying a couple songs? It makes more sense to me that playing old games would encourage those song sales.
Before your comment I thought the more likely reason that Microsoft qualifies games is to reduce the amount of development and support effort needed for their emulator. Even Halo 1 struggled to get some good framerates, IIRC.