I have Biden winning the black vote 81%-15% (4% third parties) so this is about right (considering Biden will win most undecideds). That would still represent a right-wing shift for black voters (as has been happening since 2012).
In fact there's a distinct possibility that black voters will swing right for the fourth consecutive election (2012, 2016, 2020 and now 2024). That could be enough to flip Georgia if white suburbanites don't trend further left.
That conclusion ignores the fact that tens of thousands of african-americans have moved to GA since 2020, while the amount of white residents has largely remained static.