To be more specific these two ways now form overlapping platform areas:

https://www.openstreetmap.org/way/34007202

https://www.openstreetmap.org/way/1420932643

While platforms can be mapped as a multipolygon it is not always necessary. I sometimes do it when there are multiple staircases and elevator shafts that need holes. But there is no real need to have holes for small shelters that are free standing on the platform, for example.