Not the whole source package, but we do want to remove the py2 binary.
Maybe there should be two versions of the email, with the one for py2/3
packages saying 'NMU' instead of 'removal'?
this is not how autorm works. You can't remove from testing only one of two binary package from same source package. You are removing package as a whole.
But maintainer can anytime fix that bug by removing py2 binary from source package, which is few minutes work.