A Google spokesperson explains:
Promoted pins in navigation are not new – they let people see relevant ads for businesses like gas stations, restaurants, and stores along their route. To avoid driver distraction, these ads do not pop up, expand only if they’re tapped on, and disappear quickly after a short time.
If they don’t pop up, then how do they disappear? They were never there but they go away? Double plus good.
Stop being deliberately obtuse. They pop open when you tap the pin, then disappear after a short time.