Why does implementation of make_tuple not return via brace initialisation?

To understand the question please read this answer first.

I checked different historic make_tuple implementations (including clang versions of 2012). Before C++17 I would have expected them to return {list of values ... } but they all construct the tuple before returning it. They are all along the lines of the very simplified current cppreference example:

template <class... Types>
auto make_tuple(Types&&... args)
{
    return std::tuple<special_decay_t<Types>...>(std::forward<Types>(args)...);
}

Its not wrong but the point of returning brace initialization is to construct the returned object directly. Before C++17 there was no guaranteed copy elision which removes the temporaries even conceptually. But even with C++17 I would not necessarily expect the curly braces to disappear in this example.

Why no curly braces here in any of the C++11/14 implementations?