Word of mouth seems to be the preferred method of learning on the railways. Takes less effort than reading for oneself. People just have to learn the hard way.
It's the easiest way, but not so much because staff are lazy, but more because the railway doesn't help itself. Sure there are staff who don't want to learn 'because they are right', but when the only methods of finding information are going out of your way to find it, it's simpler to listen to those 'who know better'.
Back in the days of APTIS, before the railway learnt about 'the internet', there would be a newsletter sent out (by Royal Mail) every four weeks detailing any offers the train companies were setting up (and always in advance), any changes that needed to be noticed and any mistakes from previous notices that needed to amended. With it was any pages from the Retail Manuals that needed to be changed. It was a very visible system.
Now we have a website that may or may not be changed every week at a seemingly random time of day, we have rules that change with no notice given and we have train companies setting local fares with no real information passed to others (or only to adjoining TOCs when they do). It is an almost invisible system.