It's already known using the new OPROM causes no issues to previous data, which I believe is the reason Shamino initially said is why it hasn't been updated.
The only logical reasons I can come up with are:
A) it will cost (not sure how Intel licenses their OPROMs) or
B) They just don't want to deal with the headache of users complaining if something DOES indeed go wrong - "if it isn't broken, why fix it?"
It would be nice however to hear the legitimate reason why they are not updating their top of the line boards with the latest proven stable software, though. Especially seeing as this particular OPROM enhances performance and these boards claim to be all about performance.