In theory this would work.
But in practice there are issues when connecting an external screen to the Mobile Studio Pro 16.
see : http://forum.wacom.eu/viewtopic.php?f=4&t=106
This issue is almost known 3,5 years, but Wacom never have us a solution. Which is totally unacceptable for the price we payed. It is not a pen computer we bought on AliExpress!
They even didn't recognize the issue with their MSP, In the beginning they were blaming the USB-C (to HDMI, DisplayPort, ...) adapters and the cables we used. Almost one year ago Wacom5 admitted the finally the were able to reproduce the problem (that's 2,5 year after a massive amount of user complaint about the issue. But they still didn't found the root cause, I again reported all my test resultsn which would have been passed through to the specialist. But we are 1 year later, and are still struggling with connecting external screens to the MSP 16
But some people even tried 5 different adapters.
But for me it is driver related. Because there are no issues when using a generic Microsoft driver. And before an update it even worked with the oldest Intel Iris 550 driver I found on the net.
Only stable solution I s connecting 2 monitors to the MSP 16 (may be the same but with 2 different inputs. But I guess the Cintiq doesn't have this.
So strange enough having 1 internal screen and to external screens to manage is stable, with the same cables and connectors, and even requiring more resources from CPU/GPU.