I want to get an iMac, but need Thunderbolt 3 to be able to access external GPUs. The iMac was recently updated in October, which was a little too early for TB3. In the intervening time, TB3 has become quite widely available and, for example, is expected for inclusion in a relatively imminent MBP release. Does anyone know if there is any precedent for Apple including individual updates such as a new port type, mid-refresh-cycle? I could wait a couple more months to get USB-C/TB3, but not 6-12 months for a standard major update.