This is 100% right. According to NYT, DeKalb county is only 1/3 in. Biden is up by 80k votes there (suburb of Atlanta). I believe that NYT is expecting that the remaining votes are mail in, therefore likely larger for Biden. That makes up ~160,000 votes in that county ALONE. Then more of the Atlanta vote is still missing, also presumed the mail in.
Also they have this note:
"So far, Biden appears to have flipped Mitchell County. According to turnout estimates, around 690,000 votes remain in counties won by Hillary Clinton in 2016. Trump 2016 counties have around 110,000 votes left to report. 3m ago"