The main concern with this is area:railway= was suggested long ago for the trackbed / ballasted area (smaller than a landuse=railway , or there may be no landuse=railway if elevated; while much of the existing uses are area:railway=tram which will conceptually be inside landuse=highway ). This is similar to area:highway= for roadway areas. The use of area:railway= =station etc purely adopts it as a area representation of the railway= object.
Another option I thought about is using type=boundary + boundary= =railway / something. The requirement of using rel is more complicated.
But regardless of this, what’s the view on public_transport=station again?