I don't think you are doing anything wrong; I think you are right that it is getData that changes the name. It is a pity that you cannot do this in a single call to plot, but unfortunately you need to expand the list of variables and so you cannot use the apply function to build the call to plot (in other words, you'd like to be able to do this:
apply('plot `(,@listOfVariablesToPlot ?expr ,listOfNames ?strip ,listOfStripNums) - I think I've got the syntax right there, but I have not tested this, and it won't work anyway).
I think that you just need to add the ?expr argument to the call to the plot function so that the name is as you'd like to see it, here's an example:
foreach((sig num name)
plot(sig ?strip num ?expr list(name))
I have not tested this! You might need to rework it, and possibly use getData again?
Anyway, I hope that this helps you.