It would be nice to have click and hold down the mouse wheel until the cursor changes to roam functionality in ArcMap to be implemented also for ArcGIS Pro and Runtime .NET.
Mark, what tool do you have active? With the Explore tool active, it isn't necessary to depress the mouse wheel to pan. You can pan by holding the left mouse button. If you have another tool active, like Select, then depressing the center mouse wheel does pan.
Kory, If you check out the video Mark uploaded, you'll see he's asking about holding the wheel down until the other pan functionality kicks in, moving in the direction you gesture. This is similar to scrolling a webpage up and down by holding the wheel button.
That said, I never understood why the default pan functionality you're showing disables the wheel click while using the Explore tool. It works with all tools in ArcMap, including when Pan tool is active. It's just a weird habit to use one click for 80% of situations, but suddenly switch to a different click for the remaining 20%. The wheel click isn't used for anything else with the Explore tool active, is it?