This depends on the renderer/render settings. e.g. https://openstreetmap.de/karte/ https://openstreetmap.de/karte/ always shows the german names alongside, if a

This depends on the renderer/render settings. e.g. https://openstreetmap.de/karte/ https://openstreetmap.de/karte/ always shows the german names alongside, if available. But those are set by the site owner, not the user (those are not vector tiles after all)