The design is optimized for common VR hardware running at a 3K resolution and 120 frames per second. It might not help with some future headsets, then. However, ARM hopes it’ll lead to “lighter, smaller” gear that’s more comfortable to wear.
You will have to wait a while to see any benefits. The Mali-D77 is just architecture at this point. Chip makers will have to implement the design in shipping processors, and you’ll have to wait until sometime after that before it’s available in a headset you can buy. Still, this bodes well for the future of self-contained VR — you won’t have to settle for a sub-par experience just to avoid wires.