[2020] Does the metro-intercity bus hub need a intercity bus station?

No, it won't require a regular intercity bus station. But intercity busses might take a while to arrive, especially depending on how attractive your city is and where the hub is located. If tourists aren't interested in visiting your city, you will only see very few or no intercity buses. Keep working on your city's attractiveness and I'm sure they'll start arriving at some point. :)