This looks like a pain in the ass to work with. You have to pull the GPUs through your 5.25" bay one by one and then you've got hoses sticking out the front of your case. lol
I have the 49UB8500. You are just talking about the labels by the HDMI ports right? Ignore them. I have no idea why they are there, but they make no sense.
Port 3 is HDMI 2.0/HDCP 2.2 compatible. The rest are not so don't use them unless you have to. My TV came with a little card saying as much.