So called “objects” are unitary things only because we assign them that status. They are actually composites. It would be truly strange if these objects were to fall at different rates in a vacuum.
The article fails to mention Einstein came up with this in 1915, 105 years ago. To quote Einstein. "Time is not absolute" simple description of Core Gravity Theory. Another Einstein quote: "If you can't explain it to a six year old, you don't understand it yourself" What an amazing man!