The amount of tax that was withheld from your unemployment is not affected by the $10,200 exclusion. If you already filed your tax return, and entered the tax withheld as shown on your 1099-G, that withheld tax was already applied towards the total tax on your tax return.
The recalculation for the exclusion changes your income and your tax, but it does not change the amount of tax that was withheld. The amount that was withheld from your unemployment was added to the tax withheld from your pay or any other withholding that you had. The total of all the tax that was withheld anywhere was applied to the total tax on your tax return. Withholding from unemployment is treated the same as withholding from pay or from any other income.
You will still get any additional refund that results from the recalculation for the exclusion.
