If it were known, it wouldn't be news that two independent studies discovered it.
Edit: the second link says "Being forwarded all public filings acquired and accepted by EDGAR at the same time as filings are sent to the SEC from EDGAR". It does not say "several seconds early."
If you worked trading earnings it would not be news to you. Computers are also polling other places (like company websites) to see if the content is just hidden but still available or gets accidentally posted early.
Edit: the second link says "Being forwarded all public filings acquired and accepted by EDGAR at the same time as filings are sent to the SEC from EDGAR". It does not say "several seconds early."