Devices with dTPM were released in 2006. BitLocker leveraging dTPM released with Windows Vista. Corporations have been using BitLocker w/ TPM for nearly two decades at this point.
You're referring to first usage but I think the above is about first guarantee of what ALL products in the platform will have. Corporate purchases or BYOD, you can assume an Apple product has a reasonably secure way of storing the user's VPN key or whatever.
