I recently went on a behind-the-scenes tour of the Georgia Archive and learned a lot about how they functions. One particular aspect that I learned about is Safety Vault Microfilm. This service allows counties to have their records microfilmed (I'm not sure if it's through the archive or a third party) and stored at the Georgia Archive. These microfilm rolls are not available to the public, but are stored in one of the many areas of storage that are not considered part of the Archives records. The Archive employees I spoke to referred me to the individual county's Superior and Probate Court Clerks for details on which records have been microfilmed. I also don't know when this service started.
Going forward, if you are researching at a county courthouse in Georgia that has experienced recent records loss (Hancock County, for example), make sure to ask the court clerks if they utilize the Safety Vault Microfilm service and how you might be able to access those records. For other states, ask if they have a similar service.