I doubt that locomotive hauled passenger services will ever return so I'd say that if the Belmont Grand Hibernian ever stops operating, the Mark IIIs will be scrapped. I'm not sure what IÉ's logic was for scrapping locomotive hauled services nationwide but operating railcars of upto 8 vehicles is effectively running 8 individual locomotives. The most annoying thing about intercity services being operated using diesel railcars is noise intrusion into the cabin.