From what I understand his methods are revolutionary for people with his same physiology. He and his brother were the subject of a study which seems to cast doubt on the potential of his claims for people without a similar physiology:
https://journals.plos.org/plosone/article?id=10.1371/journal...
How does experiment on his and his brother can possibly cast doubt on potential for different people? I mean, the study did not measured anything on different people.
The study showed that he and his brother, who has a similar brown fat physical makeup but doesn't follow the 'Wim Hoff method' performed pretty much the same.