As I understand it... they would have needed to "translate" the code for it to fit siege. *extreme irony*
And since they do nothing much for siege...
Don't ask me !
not redally, siege is more of just extra code in the codebase, we got all the rest of it just fine.
IBD's have been on siege before, and the 7th ani items and such as well, we still have the turnin vendor that they used to try to help fix the fact that they had mistakenly added those before and created a huge mess. (I never had any to turn in, but iirc it accepts any of the blessed items for soulstone tokens)