So I return to my first question: what is wrong with using the term “pro-abortion?” If we do not paint the term as a positive one; procedure that is not to be any more shameful than kidney biopsy have we not already lost the terminology war?
Feminists are not exactly protesting to make it legal to deliver babies. Even in places like China where abortion is co-erced, their protest against the illegal birthing is pretty weak.
When a movement tries to make abortion more available, when they want the government to pay for it, when they chide those who disapprove of abortion, they're pro-abortion.
The only reason I can think of that might make people shy away from the word "abortion" is that they don't want to be seen as favouring this:
The word "choice" attracts more people than the word "abortion" does.