I would interpret it to mean that they're meeting at the station, right outside the door to the train itself. Possibly either because they're then going to get on together, or else because only one of them is going to be on the train and the other one will meet them when they get off.
I don't how how idiomatic the English is here, though, especially if another native speaker (different dialect? I'm from Minnesota, for the record) thinks it sounds wrong. It'd be good to get clarification about whether to interpret Esperanto "cxe" in this exact same way.