Why is co_await for loop not shipped in C++20?

Question

I've seen this code from cppcoro library from github repository:

cppcoro::async_generator<int> ticker(int count, threadpool& tp)
{
  for (int i = 0; i < count; ++i)
  {
    co_await tp.delay(std::chrono::seconds(1));
    co_yield i;
  }
}

cppcoro::task<> consumer(threadpool& tp)
{
  auto sequence = ticker(10, tp);
  for co_await (std::uint32_t i : sequence)
  {
    std::cout << "Tick " << i << std::endl;
  }
}

Wherein the async_generator yields a value while can co_await and the coroutine consumer has the for co_await wherein the equivalence of:

for co_await (std::uint32_t i : sequence) {
  std::cout << "Tick " << i << std::endl;
}

is

{
  auto&& __range = sequence;
  auto __begin   = co_await __range.begin();
  auto __end     = __range.end();
  for (; __begin != __end; co_await ++__begin) {
    std::uint32_t i = *__begin;
    std::cout << "Tick " << i << std::endl;
  }
}

according to the Coroutine TS draft: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/n4775.pdf

What is the reason why for co_await is not shipped in C++20?