This is one study covering a form of life that was largely replaced during the Cambrian explosion, and took place right after massive glaciation , while the environment was very different to today, or even the Cambrian epoch.
The main point of the study is that Oxygen levels may have been lower than thought, which isn't "a problem for science" because "science" isn't even sure if the many fossils from that period were animals (and would require higher oxygen levels).
And for people here who didn't read the article: this isn't about the origins of _cellular_ life, or even multicellular life. Multicellular life had been around for tens of millions of years. And life itself had been around for billions.
This study asks "are we wrong about how much O2 COMPLEX life requires?" And we may be, Because the ediacaran had different life forms than we have now after the Cambrian explosion.