Possible to use iMac Pro as a monitor for a variety of devices?
I don't think you can use the iMac pro as monitor for other devices natively.

However there are ways that may achieve what you need.


Screen sharing. Macos has build in screen sharing capability. And Microsoft has free Remote Desktop in the app store.
Synergy keyboard and mouse sharing software from Symless. It works across Windows, MacOS and Linux. The core is free and open source, but you will have to paid if you want the GUI.