in Quimby i have an airline called Doha expressway. I fly to a lot of cities and countries but when i started a route to LAX all of a sudden i had hundreds of flight that became restricted. For example Doha to Amman or to Tehran. This is not restricted in real life and i don't know if the LAX route had something to do about it.
We implement aircraft size restrictions some time ago to combat slot blocking with small cheap planes. Thereby you cant fly ERJs on those routes. Even if you could I wont recommend flying them as costs at large airports are higher now. Filling larger panes isn't a problem, I am personally flying A380s to small airports.