I think this could be a good impetus to get rid of that. Right now the concept of 9-5 is often adopted by pure inertia even when there is no reason to do so. The day we'll have to all translate the current '9-5' to a different number, it will be a serious chance to reevaluate if that's appropriate.

For instance my place has a requirement on being there around 9:30 in the morning even though we should be part of the "Ivory Tower" club you mention since we actually work day in day out with people on different time zones.

Same with public services opening at 9h an ending at 18h, forcing everyone else to open holes in their schedule to get there.