Outlook should support External GPU (eGPU) surprise removal.
Outlook does not support external GPU (eGPU - external Graphics) scenario, which is becoming more and more common with Intel Thunderbolt capable laptops and eGPU enclosures.
Outlook should be made resilient to eGPU removal. The Graphics team published a sample illustrating how to do this: https://github.com/Microsoft/DirectX-Graphics-Samples/tree/develop/Samples/Desktop/D3D12xGPU
If the above is too much work, how about releasing its hold in the eGPU when the Outlook window is moved to the internal display, so that the user can select safe remove of the VGA controller (eGPU)?
If Outlook is closed and reopened on the internal display, it still seems to open the eGPU even when it's not displaying any content to the external display to which the eGPU is connected. So, Outlook needs to be closed before the eGPU is unplugged by the user.