If his math is correct then 8k, which is 4x the pixels of 4k, would need 4x that bandwidth, and even Intel's Thunderbolt 2.0 is "barely" at 20 gibabit/s, which means we can't go much further yet. It will be a while until we reach 80 gigabit/s.
8k is also an OUTRAGEOUS amount of pixels to throw around. Unless you're eyeball to eyeball with a 40" display, your eye can't distinguish between 4k and 8k.
