UPDATE: THIS HAS CHANGED. SEE MARCH 24 REPLY BELOW.
The IRS posted the following on their web site this morning (Tuesday, March 23).
"If you have already filed your 2020 Form 1040 or 1040-SR, there is no need to file an amended return (Form 1040-X) to figure the amount of unemployment compensation to exclude. The IRS will refigure your taxes using the excluded unemployment compensation amount and adjust your account accordingly. The IRS will send any refund amount directly to you."
At this link, it's the paragraph after the bulleted list:
New Exclusion of up to $10,200 of Unemployment Compensation
