Keeping Freeman brought a WS championship to Atlanta, so ultimately it was the right call at the time.
However, not trading Freeman led to exactly what I was warning about years ago. The Braves didn't add talent (either minor league or major league) which limited the talent pool more than it could have been. Then when he became a FA and wanted (or his agent wanted) a deal too rich for AA's taste, they let him walk for nothing and traded talent to bring in Olson, then paid him big money. In a way it was a double whammy.
If you don't trade Freeman then you pretty much HAVE to sign Freeman. That didn't happen. And the Braves farm, while producing at least one complimentary piece each year, has been too shallow for years to really help fill holes through trade.