So is the data backed up or not? If it is backed up, then simply restoring the files should be pretty trivial. If it isn't backed up and the files in question are actually encrypted, then they would be powerless to do anything about it other than paying the ransom or doing a complete reformat.
It's very likely they did have backups. I think most half decent schools or universities will have a good enough IT department to know to back up their files. There's a lot of valuable info that could get lost if they didn't.
If they did have backups then this is really a non-issue and a minor inconvenience at most since they should be able to simply restore everything pretty easily unless their backups happened to be weeks old or corrupted. The article says that the computers are still compromised and that they were forced to postpone their exams due to this which would be odd if they did indeed have backups.
I once had a network compromised by a virus which managed to get past the firewall. Fortunately, I had a backup that was only a few hours old and after a virus scan and a quick reformat, I was able to have the network back up and running in a couple of hours. It wasn't CryptoLocker but it worked in pretty much the same way. It was really a non-issue.