Its not like there is much in the way of architectural merit at the current station...
It's not really about heritage, more that for many current residents of the village, Waterbeach station would go from being in walking distance to requiring a long walk (too long for regular commuting), cycle ride or short drive. It wouldn't even be a particularly nice cycle or walk, as the multi-storey station car park will turn much of the village into a station access road.
For how small the village is, 372,000 annual entries/exits is really quite good, and given the (relatively) small size of the car park, much of that travel will be commuters from within the village. That's a substantial number of established travel patterns that'd be disrupted to make way for the (fully speculative) estimated demand from residents of the New Town.
Sure, there'd be some people moving to Waterbeach due to the (comparatively) affordable homes within commuting distance by rail to Cambridge and London, but there are no guarantees. If there weren't capacity constraints, there'd definitely be merit in keeping both stations, as rather than this project being a 'relocation', it's more like closing 'Waterbeach Village' station and opening a separate 'Waterbeach New Town' station.
Presumably some of the more optimistic estimates for demand from the new station do predict higher usage at the new station than the current 372k, in which case it's a net positive to have the new station. If any of that higher-density development right by the station (shown in some DevCo images) happens then I can certainly see it exceeding 500k. But this is certainly a project with both many winners and many losers.
www.bbc.co.uk
