That was my assumption...
Now.. the fact that these boys all pre-registered doesn't really mean anything because that happened prior to LS being missing. BUT if they don't cancel registration they're still responsible for tuition payment... so I would THINK that if they weren't coming back IU would know about it by now.
The story did say that IU doesn't actually consider them "enrolled" until the first day of classes, but I can't imagine that there's not some penalty for a late disenrollment! And even though these kids come from big $$, their families didn't get that way by throwing money away on unnecessary fees.
Just saw this post and everything you say is perfectly logical except undergrads are NOT logical or responsible. I teach undergrad students at a fairly major university and the policy here (which may be different at other places, but wouldn't be that different) is that if you do not withdraw yourself you do owe. You do not have to pay immediately though so the bill may come or collections may start weeks after the semester starts. They threaten to drop you if you don't pay here, but they never do.
Tons of students have no idea that they are not automatically dropped from classes if they never show up. It makes me angry because I do not feel like someone who never shows up should be forced to pay. I have even been a nosy person and emailed students enrolled in my classes that never show up. I cannot drop them by myself, but if they drop by a certain date they either don't owe at all or owe a lot less.
On a more personal level, my parents paid for at least three semesters for my brother that he never showed up for, but was still charged for the classes. Probably a bad choice on their part to bail him out of bad decisions multiple times, but it isn't unfathomable to me that other parents may make the same decision.
Sorry for a very long post that is probably only mildly relevant, but I wish I could tell all undergrads that universities can and will charge you for classes that you do not physically withdraw yourself from. Not showing up and not paying the bill beforehand will not withdraw you unless you have one of the better universities with a fair policy.
Anyway, I do think it is within the realm of possibility that some people signed up, didn't withdraw, yet won't be showing up. For that reason, I will be interested to see whose butts are actually in classroom seats the first week of class.
Edit just to say I love my undergrads dearly and some are very responsible and logical. I just don't think it clicks for a lot of them that you do have to withdraw from classes formally and, of course, universities love that because they can charge people for services never given. It is just frustrating to me on a professional level to see students getting nailed financially for something they may not entirely understand or be mistaken about.