Repro steps:

1. Open Unity and create a New Project
2. Click on the "Main Camera" or "Directional Light"
3. In the Inspector window select and press the right mouse button on the name of the Object

Expected result: The "Cut" and "Copy" options to work/not be grayed out
Actual result: The "Cut" and "Copy" options are grayed out

Reproduced with: 2017.2.0b3, 2017.1.0f3, 5.6.2p3, 5.5.4p2

Note:
Changing any property of either the camera or the light fixes the issue
Restarting the Editor causes the issue to reappear until any properties are changed in the Inspector
Commands like "Ctrl" + "X" or "Ctrl" + "C" still work ("Cmd" for Mac)