It seems like the IRS does not allow a superseded 1040 to be e-filed yet.

Publication 4164 (for the 2021 processing year):

The superseding return designation is available for Forms 1041, 1120, 1120-F, 1120-S and 1065.

The superseding return designation is not available for Forms 990, 990-EZ, 990-PF, 1040, 1120-POL and 2290. The amended return box must be checked for any subsequent Forms 990, 990-EZ, 990-PF or 1120-POL returns to be accepted.

https://www.irs.gov/pub/irs-pdf/p4164.pdf#page=24