Oh, I very much doubt that. If anything, I'd wager it's a purely technical/process decision. I bet there's some ancient mainframe deep behind that API that runs batch jobs and reports overnight.
The whole student management system at my uni (which was implemented at the start of this year) is like this too, down between 2am and 4am to 'synchronise the timetabling system'. I think it's to do with the massive Oracle backend, but I don't really understand the need.
