I see your point, but I think it's rather semantic. I agree with seishonagon below: Maybe we're not redefining the word "rape," but we are redefining "which of the things that we call rape are going to be allowed to receive funding."

Maybe because the word "rape" is used in both circumstances it gives people the impression that there is no redefinition going on because the words being used are literally the same. Imagine if we chose instead to use two phrases: "assists" and "denials," and said we'd pay for assists only. That makes it clearer what's actually happening--except for the problem that not using the word "rape" obscures the fact that both the "assists" and the "denials" are actually parts of the *same problem,* which is the most salient point, and that is exactly what the politicians who craft legislation like this would like everyone to forget about.