We need to stop focusing on the specific protocol when it's not relevant and focus more on the patterns. Wanting RSS, specifically, made sense back when everyone had an RSS reader, the same way it makes sense to have an HTML website today because everyone has a web browser. But since very few people have RSS readers now, there's infinite flexibility in the format you use to provide your feed. The most useful is probably a phone app that vibrates your phone with a notification when your train is delayed. RSS can be provided as an option.