If you look at the length of time it's taken to build the new Stirling to Alloa line and the Bathgate line, places where the majority of it was on the previous line, and for important commuter links, then I doubt they'll be moving the line just to accommodate AFC. What's wrong with buses? They already run a P&R scheme, it could work just as well, and there's the potential for a lot of carparking to be available up there too.