That is a good point. I just went and checked the IIM B website and you're right. For general candidates you need have 85% in every section of the
CAT and that is the same criteria that holds for GMAT students as well. Going by the way they described it, I would assume that it holds true for AWA as well.
[Update] I just realized that the data there on the IIM B page was for the previous year. They haven't listed any cutoffs for this year. However, there is no reason why it should drop. As far the AWA is concerned, we should confirm from IIM B adcom.