Very unlikely they are about to replace cables at that end unless they are shown to be faulty. The important cable is from the wall to your components and making sure your electrical is able to run Clean without interference and at the same time protects your investment, I use a Belkin PureAV PF40 line conditioner and it works great and got it with big time discount at Ecost once in the shopping cart.
So good connections then from the STB to the TV's with either component or HDMI/DVI and clean power/protection and you should be fine. I've never had Satellite but many state they compress HD alot affecting HD. If there was a problem exteernally it would impact everyone in the region but since it's buried or elevated and out of reach it's unlikely, if you do what you can to maximize the feed and issues occur then they may be able to test the lines externally.
It's sort of like when I suspect issues with my five T1 lines on my network I have to work from my equipment back to the smartjack and test before calling my Telco to exclude my equipment otherwise I get a billable service call at $150 per hour when they come out to test their end (if they are unable to do it remotely) - so take care of your end and minimalize electrical issues within the home and then work backwards knowing you've done what's needed internally rather than assume age of the cable has a role. I'm forced to do it so I don't waste my IT budget resources out of panic during a T1 loss. Usually issues occur from auto accidents, weather, rodents chewing through or construction diggers that fail to call Ms. Dig, or the smartjack locking up.
But after you've done all you can and issues persist they can come out and test the lines from the local box they may be connected to that feeds your home and they should be able to feed and test from point-to-point and I've heard of this being done and they can replace the section depending on the logistics.