And no, my information, isn't authoritative. I just know that my son isn't currently worried about catching his 5:30pm flight out of Denver. We did book on Southwest, so if something changes, we can revise the flight schedule. But, if your cadet checks with his AOC, I'd consider that authoritative.
By the way, I know some C4Cs are hesitant to ask questions of their AOC, but they shouldn't be. The AOCs actually want to know the cadets - at least the two my cadet has had did. And, confirming the leave time might be a good way to start communicating with the AOC. I know one brainy kid who did well on his knowledge tests but basically hid and tried to stay out of the way of his AOC and upper classmen. He was disappointed to get a "C" for his military grade first semester. When he summoned the courage to ask his AOC about it, he was told "I don't even know who you are. I've never seen you do anything. So you can't be more than average." So, don't take the "stay under the radar" advice many give to C4Cs too far.