There are numerous ways to embargo data and make it available to reviewers before publication and to the public after publication. [1] This isn't a new idea. They simply did not do it.

Nature is a "premier journal" known for publishing cutting edge research. Any data - in this case a bunch of numbers - used to support the conclusion should be made available. I am sure there are disciplines where the evidence would be difficult to provide directly - fossils, physical items etc. Maybe this PI did the experiment himself - thought he won a Noble - only to find he could not in fact reproduce the results after publication - oops. IMO Nature did not do its job. Just pointing that out.

[1] https://plos.org/resource/how-to-store-and-manage-your-data/