Unless they are going app only with it. The current 4K box can not do it.
So with BT sport 4K UHD HDR launching later this year. I'm assuming a new BT box will be launching too?
and HDR is an even bigger diference.
You've obviously not seen HD and 4K side by side. The difference is amazing.
Whether there is a difference for you depends on three things
a) Size of the TV screen - on my 40" the difference between HD & 4K is fairly marginal
b) How close you sit. I need to sit closer than about 5ft (see chart below) to see any difference - and I find that too close.
c) How good your eyesight is.
There is an interesting chart ( it only goes up to 4K but illustrates the point) at http://s3.carltonbale.com/resolution_chart.html
I have an LG55OLEDC8PLA which supposed be quite good and my eyesight is good. I don’t sit too close and am blown away by hdr and 4K on Netflix and Prime but the footie on 4K looks very little different from the hd version.