Some data consumers expect that, if any name:*=* tags is present, one of the name:*=* tags matches the value of name=* in order to know which language name=* is in. In fact, one of the osm-carto developers has experimented with hiding the label if the name=* isn’t duplicated in one of the name:*=* tags, although in this case, it would’ve been able to infer that the name=* is in Portuguese, thanks to default_language=* on Brazil’s boundary relation.