Despite this, the disengage message doesn't display ANYTHING for me. "Press to disengage."
That feels like a bug to me. I thought that they had fixed that blank prompt, but it happens when you don't have a key bound to that function. See the "Ship Controls" prompt on the screenshot above. It can certainly happen with the more "chatty" messages that appear in the HUD, when you do indeed get the "Press <nothing> to do whatever" message.
I note that the SC and Hyperjump buttons can be the same key and are the same key on the default bindings. They are usually moved onto different keys by players who have enough keys because you can do things that you can't do otherwise. There are three keybindings -- both SC and Jump, just SC and just Jump. I suspect that the "Press To Disengage" message is only picking up one of those bindings, when it should be checking for both of them.
So you are correct when you say that it is significant work to do, but it's such a minor thing that I imagine they won't bother. In fact the bugged message is probably more acceptable to more players. If it works for newbies with the default bindings, then it is good enough.
Of course the players on consoles, that don't have enough keys to separate the functions, will not benefit from seeing the message without the immersion breaking binding.
Personally I don't care what that message says because I never read it. The instant I see a flash of blue, I hit the button.