Showreel GT Races

How comes these aren't available in-game? If someone at the studio made these for the showreel, why aren't they in-game as missions? I installed my wheel thinking I could play these on Hirochi for the week end only to find out these don't exist
There's a real lack of racing missions right now, even if there's plenty of proper race cars and a few track there's barely anything to race offline, what's the reason behind this?