I agree. The comment is correct in that it sort-of violates the "purity" of std::indirect that it has this pathological in moved-from state, but it's only an issue when directly using moved-from objects, which is something you essentially never do. Exactly what you say, "in practice" this never happens. Throwing the move constructor out because of it would be throwing out the baby with the bathwater.

std::variant has a similar issue with valueless_after_exception, which given the semantics of the language, it has to have. But similarly, this essentially never happens in practice, and I've never encountered a bug with a valueless std::variant.