Perhaps you can play her temporarily for 48 hours; like the temp kombat pass?
Possible, if it isn't, and I don't think it is, I expect a patch in a day or two, since MS gets a small cut of all DLC sold, they will be much more lentiant on Q&A.
Also since its a compatability patch, all they have to do is flick a switch and make it so you can't access her again with out the proper key, so in the end no one is actually going to get her for free, unless they unplug there xbox and never update again.
