Hello
I will recommend all people not to go for the new macbook usb-c only line.
all my usb devices get unstable connections. hdmi as well. better cables help, pram reset helps, but don't solve the problems.
not sure if it is a firmware problem or if usb-c plug is not stable enough physicaly.
I got the macbook into apple care and they said no problem found. Of course it is something that appears randomly and the devices will reconnect eventually.
If you shoot tethered that will not be a nice surprise on the job. Restart computer, pram reset and so on in front of the customer is never nice.
best regards