It's a common feature on all cinema cameras, who traditionally required lots of memory and rarely/ever had internal memory cards (for heat reasons). Some hybrids like the new Panny and maybe Fuji has that as well. As far as I know, not applicable to stills and not on any of the flagships from Nikon, Canon, and Sony. In many cases, that's done through the HDMI, not USB connection.
Two trends to watch for re storage: (1) direct to cloud, similar to what Fuji just released on the red-hot 100vi with built-in frame.io and (2) built in ssd like Hassy started to do. I'm not really seeing anyone investing in external SSD recording for stills.