Lothian Buses have indicated their expectation to withdraw some services in the near future due to staff shortage (announcement linked below:
The method of communicating withdrawn journeys/services isn't made clear in their statement. Perhaps nobody would notice cancellations on some of the more frequent routes, but maybe not so good if you're deliberately waiting for an express bus and don't know it isn't running.
Maybe they'll publish an emergency timetable across the network, similar to last year.