So here is the thing with Apple including Transit data. Apple can only include a particular cities transit data in the Maps app if there is an API available somewhere for it. It is also not feasible to roll out 50+ cities in the beginning. The idea is to make sure that, at the beginning, the few major metro areas that were announced, work correctly. After that, possibly by the end of the year, I expect there to be an update to the number of cities that are included in the Maps app, transit directions wise.