MWI or Parallel Worlds is an interpretation of QM, it is one of the 15-20 major interpretations of QM. Nothing at all wrong with MWI. Sean Carrol speaks kindly towards WMI and I have tended to agree with his views over the years. I don't see any wild claims being made that would warrant a major reaction, but I would agree Willow's results are so impressive that it should lead one to consider at minimum that it counts as evidence in favor of the WMI. I don't see how this doesn't count as evidence for MWI.