The article later states:
"increase transparency in the agency’s decision-making by requiring all underlying data used in scientific studies to be made publicly available"
That sure sounds like a good thing. It would of course limit the use of data that is unreproducible due to being kept secret, but that isn't bad at all.
"designed to restrict the agency from citing peer-reviewed public-health studies that use patient medical records that must be kept confidential under patient privacy laws."
and the next paragraph:
"Such studies include the Harvard School of Public Health’s landmark Six Cities study of 1993, which established links between death rates and dirty air in major U.S. cities. That study was used by EPA to justify tighter air-quality rules opposed by industrial polluters."