In case you missed earlier post. Still no clue as to why? https://www.atlantaradioclub.org/atlanta-hamfestival.html
The statement to which you linked clearly indicates that they had a problem securing the desired site: Due to ongoing issues, that we have not been able to satisfactorily address at this time, related to our return to the newly renovated [Jim R Miller Park, it’s home since 2001], it was decided in the best interests of attendees and vendors alike to cancel this year’s show.”
Then just say, "we are not able to use the park because..." It's not ready. Someone forgot to pay the deposit. Rabid terrapins. Ebola. Could not agree on fee split between clubs. Sink hole. Terrorist threats. Did not want to share with KKK (SPLC) rally. Air conditioning not working. Road closed for repairs. Toxic waste found. The fence isn't up yet. "ongoing issues" ? <-<-<-<- ...
The statement refers to "ongoing issues" and also notes that they are trying to arrange for the site next year. Most likely, they don't want to be specific about what those "issues" are so as not to jeopardize those efforts.
An operator on two meters whose call I don't recall said that the venue (which had apparently torn down the old buildings and built new ones in their place) did not have a "certificate of occupancy" from the city for its new buildings. With a whole year to sort this out, I presume the venue will be ready for the 2020 Atlanta Hamfest.