For USB-A, that's explicitly not allowed. From the standard: USB Type-C receptacle to USB legacy adapters are explicitly not defined or allowed. Such a

For USB-A, that's explicitly not allowed. From the standard: USB Type-C receptacle to USB legacy adapters are explicitly not defined or allowed. Such adapters would allow many invalid and potentially unsafe cable connections to be constructed by users. For DP and HDMI, I haven't seen the standard so I don't know if they are allowed, but they probably aren't, because they would be confusing for users. Such an adapter would be a USB-C "sink", and when you connect two USB-C "sinks" together, nothing happens (it would be like connecting together two devices which only have the classic USB-B port). So if a user tried to use a pair of these dongles together with a USB-C cable to replace a "native" DP or HDMI cable, it wouldn't work.