I think it is great, but I'm baffled at the timing.  When have they had time to do this?

The IRS was scrambling to deal with the CARES Act.  Then peak tax season.  Then the shutdown, dealing with EIP, and whole bunch of new laws they need to implement into their systems both now (for payroll) and for the 2020 year.

When have they had time to add the 1040X???

As for Intuit, my prediction is that they won't do it with the 2019 software, but might starting with the 2020 software.  But I hope I'm wrong and they do add it to the 2019 software.