Thank you very much for pointing it out, I was not aware of that discussion!
The decision there was the following:
To sum that up in English, if I understand it correctly:
Stations should remain tagged as railway=station nodes
The station area (defined by local railway regulations) should be tagged with landuse=railway
This area should be linked to a public_transport=stop_area relation.
Objects tagged with public_transport=platform, railway=stop, railway=subway_entrance, landuse=railway, building=train_station and railway=station or railway=halt should be added as members to this relation.