Lost to these nonscience students is an exposure to cutting-edge science and the methods of science taught by professors active on a daily basis in their exploration of nature. In how many AP classes in high school does the physics instructor say, "At the last American Physical Society meeting, one of my students presented a paper on this very topic"? Or, in an astronomy class, "My upcoming observations using the Hubble Space Telescope will address this dark-energy issue"? Identical scenarios exist, of course, for science and engineering students who miss out on university-level introductions to the humanities and social sciences taught by active scholars in those areas.From what I remember of all of my introductory courses in college, there was very little "cutting edge" research discussed. And thank goodness for that! It's an introductory course. When I teaching introductory econ I rarely mention any new research and if I do, it is illustrative of some larger point (say an empirical paper on a price control). You don't want to overwhelm the students and, precisely because it's advanced, they probably won't understand it anyway. Imagine having a long discussion of the Higgs boson in Physics 101 when you're still trying to wrap your mind around Newton's Three Laws of Motion.
OK so you stick to offhanded references, not in depth discussions. Big deal. Admittedly, mentioning something cutting edge is cool to do and it can get your students interested in the introductory topic or illustrate where the puzzles in your discipline remain. Disallowing AP credit for college would generate these additional benefits but they are small. They come at a cost of the student not taking a course that's completely new or paying tuition for the semester that can no longer be avoided.
I had a student in introductory econ who didn't have to take my class: he had AP credit. He took it anyway since he'll be taking future courses from me, but I can't help but think that it was largely a waste of his time.