I don't think my proposal should be off the table for scope reasons because it requires the syntaxes to be completely unified and interchangeable, which will be impossible if the current PEP is accepted. I guess it's technically possible to still have the pattern-matching syntax be slightly different from extended assignment statements, but I think that would just unnecessarily complicate the language, force users to be aware of the subtle differences when writing code, and potentially cause users to make mistakes.