Wow, raphschru, thank you for those examples; they really highlight both the power and possible pitfalls. My opinion is the last label should take precedence (so "X", "Y", "Z", and ""This is just a comment" in your examples), but I could see how it might not be possible to implement changing labels on a single wire.
Wire labels are not names, in my opinion. Comments should not change code. If you want to name the items, do it formally with a Coerce To Type node. Or, you know, make a constant and wire the middle terminal of the bundle... 😉
Though I wouldn't use the wire labels, as they are used as documentation, I would really like a way to change the name of a wire, so as to be able to define clusters like this.
A change in name is a change in type. It is nonsensical to say that you want to rename the type without changing the type because the name is part of the type. You wire the identical data structure into the center as into the left but with a different name.
Imagine an output of a subVI that is a SGL named "Process Variable". You rename using Coerce to Type to be named "Temperature". Later, someone upgrades the subVI to use DBL, but no-one remembers to change the SGL constant. Now you are losing precision without realising it, coercing a DBL to single precision. A bug. At best, you'll waste time running through all your code hunting for coercion dots.
