Someone downvoted you but you are correct. The report used assumptions based on satellites not even made of the same materials as starlink satellites.
Among other things, SpaceX said the FAA's debris estimates were based on a 23-year-old study of satellites that were made with different materials than Starlink satellites. SpaceX says its own satellites are designed to burn up completely when they reenter the atmosphere.
The FAA report to Congress did include a caveat that said, "If SpaceX is correct in reporting zero surviving debris, as SpaceX reports in FCC filings, and Starlink is a fully-demisable spacecraft, the rise in reentry risk is minimal over the current risk."