The TV doesn't have Display Port? The 1.3 spec handles 4k @ 60hz no problem and is already available on the 600 and 700 series.
You mean DP 1.2 can already handle 4K @ 60Hz. DP 1.3 will allow for 4K @ 120Hz and 8K @ 60Hz.
Also DP is mostly a monitor/laptop connector while HDMI is meant specifically for TV's. There's no reason why a monitor can't have HDMI, or a TV have DP as it's up to the vendor to support it.