Judging by the track, not really anything close to an unqualified circumnavigation. A near circumnavigation of the Antarctic continent is more accurate with the qualifier. If someone at the South Pole dances around the actual Pole, would that also be a circumnavigation? Qualifiers help to disambiguate.
Still, it's all good science and engineering, especially getting the balloon to maintain shape and altitude despite changes in temperature, even if the reporting is ambiguous.