Do you mean the re-routed Þórsmerkurvegur e.g. https://www.openstreetmap.org/way/886779446 ? or the track? Þórsmerkurvegur looks to have been adjusted in https://overpass-api.de/achavi/?changeset=99606665 and looks to match some aerial imagery (Mapbox/Maxar/Esri non-Clarity), but I haven't been on site to verify.