October numbers are missing due to the federal government shutdown, noted in the chart title. BLS couldn’t collect the data.
As for revisions: BLS does revise monthly employment data, but unemployment rates by race are typically stable in revisions. The seasonal adjustment factors can shift slightly, but a 6.4% → 8.3% change is far too large to be explained by statistical revision. That’s a real 1.9 percentage point increase.
For comparison, the 2008 financial crisis saw Black unemployment rise about 5 percentage points over 18 months. A 1.9pp increase in one year is significant and won’t be revised away.