I suspect the choice of location has more to do with convenience for freight
Seems likely - maybe is was considered but would a 'freight only' airport be something that was possible, take it all out of heathrow (more space for passengers) and stick it in a more specialised airport somewhere (specifically, somewhere else where they won't start flying over my house :))
Seems likely - maybe is was considered but would a 'freight only' airport be something that was possible, take it all out of heathrow (more space for passengers) and stick it in a more specialised airport somewhere (specifically, somewhere else where they won't start flying over my house :))