If the new stimulus package passes with the $10,200 from unemployment tax free, how does that work if I already filed this year?

That tax law has not yet been signed into law by the President.   When that happens then the IRS will need to change the tax forms, the programmers have to change the software, and then the IRS has to approve of their software.   That will take time---we do not know yet when all of those changes will be accomplished.  As soon as more is known, TurboTax will provide information.