My understanding of it is Matt Ownby (Daphne Creator) had to jump through all sorts of legal hoops to even make his site/releases possible and it wouldn't make sense too me for MAMEdev to mimic that same behavior.
AFAIC Daphne is more of a movie player than an emulator anyway, even though on occasion those games can be fun to play as well.
I could very well be wrong, but that's how I currently understand it.