I went there today and verified the information provided at https://www.wien.gv.at/bezirke/margareten/verkehr/umleitung-rechte-wienzeile.html. This road is closed until the construction work of the new subway station Pilgramgasse is finished. So I tagged this road as highway=construction, construction=primary and updated all bus routes, see https://www.openstreetmap.org/changeset/98907851.