Having had a paper planner in high school I don't recall there really being many issues with rooms needing to be swapped or teachers being ill having an impact. If the teacher is ill, the other teacher just takes their room.

Having a digital schedule almost gives the school the ability to be more relaxed with the schedule, as opposed to it being built around a schedule that can hardly move. There is an important part of school which is revolved around routine. I remember it only took a few weeks in the first term before I'd be walking to classed without needing to read the timetable at all.

It's inevitable that we end up moving down this route, but lets not forget the old solution worked just fine and meant you needed a pretty good reason to change the timetable.