There is no longer anything that displays the extremely important information of the airport code when choosing locations. There's absolutely no reason that can't be present, and it's removing vital information, especially for areas with multiple airports
If you’re planning a trip, when you type the location in the “Leaving from?” and/or “Going to?” field, you’ll see the airport code pop-out at the bottom-left of the field.
M L commented
However it disappears rather than remains displayed when, for example, going on to add other fields, it's only visible when the menu is visible.