I agree that if we are designing the desirable future state to aim for, it’s much better for Python’s parser to have a mode where it simply preserves comments in general (mypy can use this mode and retain greater independence and flexibility in exactly what comment formats it supports) than for the parser to care about the content of those comments at all.
There’s also a group that met at PyCon to work on standardizing on a Python CST parser that preserves all syntactic trivia (comments and white space), for use by linters, formatters, refactoring tools, etc. LibCST already exists in this space and has a new experimental parser that supports 3.10+. One possible future is that Python’s built-in parser stops preserving or paying attention to comments at all, and mypy switches instead to a CST library like LibCST. But there is also some extra cost to whitespace parsing, which a type checker doesn’t need.
Carl