I'm guessing but 99% on the certainty of this, it was censorship. Nintendo even post MK2 had a bug in their ass for a few more years yet about stuff, and even if they did relax, they were a little less(not by much) relaxed than Sega. Sega slashed up anything slightly demonic, evil, and symbols of evil on the Devils Crash conversion Dragon's Fury. They likely just didn't want to have their work mutilated into something entirely different as it would need far more manipulation than the older title.