Dual-layer UHDBR discs (66GB capacity) will support a max bitrate of 108Mbps, while triple-layer discs (100GB) will allow for up to 128Mbps. With the increased encoding efficiency offered by H.265, 128Mbps would theoretically allow for a (Main 10) 4K video stream at 256 FPS, or 8K (7680×4320) at 64 FPS. That's to say nothing of the rest of the hardware chain, too:
HDMI 2.0 can only transport up to 4K @ 60 FPS, and there are no 4K TVs on the market capable of higher than 60 FPS at the moment. It bodes well for the future-proofing of the new UHDBR standard, though.