Because the generator does not see the generated union type symbol yet (and thus does not recognize a possible impure value type); value type union types are added to the value container.
Info on why this issue has been up for as long as it has:
I'm putting this on the backburner until I get around to rewriting the generator fully around symbols.
Because the generator does not see the generated union type symbol yet (and thus does not recognize a possible impure value type); value type union types are added to the value container.