I think the most you can do is, AFTER the baby's born, if he or she has proven to indeed be a dream baby who sleeps all the time and indicates the desire to BF by wriggling or snuffling rather than roaring... you could talk to your professors (with your adorably sleeping baby in the sling, so they can see you're telling the truth!) and ask if they'll make an exception. It's always possible, especially as the policy doesn't specifically say "Not during lectures".
I remember a baby coming along to one English lecture one time - a slightly older baby, she was crawling up and down the aisle at the side. Honestly, it was distracting, because I love babies and kept gawking at her. :p Then again, because I love babies I wasn't annoyed by it at all. I thought it was rather nice, actually. But I can see why everyone bringing babies could have been a problem. Go to any church where babies are allowed in the service, and you'll see people have vastly different ideas on what constitutes "acceptable noise" during the service. Some will whisk their babies out the back if they so much as wake up, while others will let them bellow for three or four minutes by removing them. Assuming churchgoers aren't, on the whole, significantly less considerate than college students, allowing any and all babies in probably would result in some significant distractions. I like the thought of a more relaxed, non-lecturey, family-friendly environment, sure; but that's not where most unis are these days.