I think the answer to your question is yes and no.
I'm pretty sure they are RJ6 coax cables which will carry an HD signal from the dish to a receiver. However, I don't believe most receivers/DVR's have a coax HD output so you won't be able to simply put your receiver between the dish and the box and have HD on all of your TVs.... unless they each have their own receivers.
I converted my 07 Ellipse to all HD but running HDMI cables from the receiver to HDMI splitters and then HDMI cables down through the floor, under the coach, and back up to the TV's in the bedroom and outdoor entertainment center. You learn a lot about your coach when making cable runs like that.
Good luck.
Rick