Posted today.  What's interesting is that the people who usually accept IRS "guidance" as gospel, are still posting comments about how they don't want to mail anything to IRS because they are certain it is not being opened.  This is probably going to be an Urban Tax Myth for another 5 years.  

The IRS is now opening mail within normal timeframes. The IRS has also made significant progress in processing prior year returns. As of April 9, 2021, we had 1.5 million individual tax returns received prior to 2021 in the processing pipeline. Including current year returns, as of April 9, 2021, we had 16.2 million unprocessed individual returns in the pipeline. Unprocessed returns include those requiring correction to the Recovery Rebate Credit amount or validation of 2019 income used to figure the Earned Income Tax Credit (EITC) and Advance Child Tax Credit (ACTC). This work does not require us to correspond with taxpayers but does require special handling by an IRS employee so, in these instances, it is taking the IRS more than 21 days to issue any related refund. If, as a result, a correction is made to any RRC, EITC or ACTC claimed on the return, the IRS will send taxpayers an explanation. Taxpayers are encouraged to continue to check Where’s My Refund? for their personalized refund status and can review Tax Season Refund Frequently Asked Questions.

https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue