The integrated holder/changer (room only for two tips) detects when you're making contact with it and removes power from the iron while in contact. Same with the iron holder in the main stand.
I guess if the stand doesn't have a connection from the manufacturer, it would be simple enough to solder on a bonding wire.
Actually, contact with the stand results in sleep mode until a configurable timeout then hibernate. Contact with the integrated holder goes directly to hibernate.
Sleep mode keeps the iron warm (I have mine set for 150c). Hibernate doesn't heat the iron at all.
I've come to really like the sleep/hibernate features. I don't worry nearly as much about leaving my iron on by mistake.