bifurcation works by dividing x8 into two x4/x4 so there is no increase in load on the motherboard or pcie lanes. so there is no obvious reason why it cant do this. maybe they thought noone will need it?
anyway its annoying because its on all their other motherboards. you can run 4 gpu in one slot if it supports 4x/4x/4x/4x quad bifurcation, which they usually do on x16 slots.
so there really is no benefit to this motherboard over other SM boards except for not needing simple cheap non-PLX pcie splitters
i mean i love it, but i feel a (little) bit cheated by the lack of Bi.
and OH MY GOD no open ended PCIE slots was a huge shock as well! what were they thinking there! such a pain to not be able to throw in a simple video card or x16 storage cards directly.