Thanks for pointing that out. I should have noticed that you were on Xbox; sorry for missing that. Unfortunately, with Xbox, bespoke airports are installed for you automatically. It would have been installed when the Game of the Year Edition came out.
I say “unfortunately” because on Xbox, there is no way to uninstall these items. Other users have reported that when they buy another airport where a bespoke airport already exists, they can see both airports on top of each other. As far as I am aware, there is no way to fix that except to get a refund for the airport you just bought and delete it.
See the following Wishlist topic requesting the ability to delete this content:
I’m not sure if you use the voting function in the forums much, but you can vote for that Wishlist topic, and the development team gives things some level of prioritization based on how many votes it has. You can also vote for your own bug reports, like this one (which I voted for!).