Thanks for confirming my finding RoyLi! As you suggest it is indeed a workaround to overlay the map with a transparent XAML element and work with that element's pointer events - but that unnecessarily increase application complexity - and as you said this isn't really an ideal situation as then the user actually interacts with the invisible element instead of the MapControl.
This did not work in this way in Bing Maps WinRT API and the PointerMovedOverride event is working normally - so I assume that this should be the case in Bing Maps UWP API too.
I have been working with a vast range of online map SDK's but PointerMove event handling were all implemented correctly (ie same way as in WinRT API). The documentation of the UWP SDK for the PointerMoved event states "Occurs when a pointer moves while the pointer remains within the hit test area of this element." - but its not. I see you are a Microsoft employee - would you mind to log a bug report on this?
Thank you.