"growing acceptance that joking about raping women is becoming less socially acceptable"
There is growing acceptance for it that is conversely becoming less acceptable?
(Edit: Sorry, I reread the sentence and have now figured out what you meant. My bad. The rest of my post still applies, though 
)
I actually think that it's been unacceptable and it remains unacceptable, in fact if it wasn't unacceptable to begin with the so-called "shock value" (shock, yes, value not so much) of the comments wouldn't be there to begin with, which apparently was this a-hole's intent or shtick.
I think the speaking out around it probably raises awareness, which is of course a good thing, and certainly may make comedians look at their material through other eyes. But I don't think there has been much change, up or down, in the general acceptability level of this sort of thing.
Edit history
= new reply since forum marked as read