It doesn't disappear like you are stating, I know what you mean (like on old Dell laptops when you'd boot them without hard wire and the wired NIC wouldn't even show in Network Connections). This still shows the wireless nic, it simply states that is isn't connected to a wireless network at the moment.
In my mind that is better also from a network admin side, as it means unnecessary connects to an AP are avoided so an AP isn't sitting there with 30 clients "connected" but not transmitting/receiving. If there is a 30 client license limit on the AP, that could pose an issue as well.