Hi,
The idea is nice and actually there is a way to do it currently.
Pick Material from Object is intended for [Compact] Material Editor but not for Slate Material Editor, apparently. You can see that in the Hotkey editor. Setting a hotkey will work for [Compact] Material Editor but will not for Slate Material Editor, which is strange indeed. In fact, such hotkey action is present only for Material Editor group and is not in SME group, when selected from the dropdown in Hotkey editor.
Meanwhile Get from Selected works as expected.
That means you can set a hotkey for Get from Selected (for SME group), select the object in VFB by Pick, go to SME and hit the hotkey.
Hope this is a good enough workaround.
Meanwhile a feature request will be created for a more convenient shortcuts for selecting objects and getting materials from them - e.g. Ctrl + Click for selecting, Shift + Click for getting material etc.
(Internal ID=1003649907)