Perhaps, but I don’t see how it’s relevant here. The passenger platforms of Grand Central extend under the same city blocks, which would put its centroid in a misleading place as well. No matter whether you’re a passenger, an employee or a railroad enthusiast, the best place to put the label at Grand Central (and possibly every other terminal station) would be close to the zero milepost, i.e. the beginning of the tracks.
I’m not against using railway=station on an area, but it doesn’t solve the need for a manually-placed label node. A station is not just an area containing railway infrastructure—it is also a linearly-referenced point feature that can be described as a milepost on a route. For example, New Haven Union Station is 72.3 miles along the NYNH&H Main Line from the aforementioned zero milepost (source PDF):
Each of the stations and junctions listed above is conceptually a single point, and there is typically a sign on the ground with matching name and milepost. They have surrounding territory, defining what infrastructure (tracks, signals, platforms, etc.) is associated with the station. But many of them have lopsided territories, and the location of the sign is not always near the center. With railway=station as an area, a lot of stations would be given labels that don’t line up with where the station nominally is.
Stations and station territory are two associated, but different, concepts. railway=station as an area may work for the majority of small stations, but there are a lot of edge cases that would be better modeled as a separate railway=station node and landuse=railway area.