OpenStreetMap is fundamentally a database of map data. It provides information like "Ottawa is a capital city". Other apps and websites like the Weather Network use the data, but how it is displayed is up to them, not OpenStreetMap. They could, for example, use their own list of "cities to star" rather than OSM's "this is a capital city" record.

That said, I actually do see a star for Ottawa at The Weather Network.