On pydev, I explained why I think the bug-enhancement policy does not necessarily apply to IDLE, starting the the fact that IDLE was treated as exceptional and not considered bound to normal policy when it was considered for deletion and ending with the fact that exclusionary dichotomous classification is inherently ambiguous in the absence of specification.

Leaving that aside, the right-click context menu is not mentioned in the brief Library manual chapter on IDLE. It is a GUI matter. I suspect that the docs also do not specify the right-click behavior of the standard interpreter either. 

The apparent external GUI standard, at least on Windows, is that context menus have copy, cut, and paste entries as appropriate. I am pretty sure that this could be found in an MS document entitled something like Human Useability Guidelines. By that standard, it was a bug for those to be missing. I know Apple has interface standards docs also, but I don't know what the standard is.

For instance, Firefox has Cut Copy and Paste within this edit box, with the first two activated when a selection is made. Outside the edit box, only Cut appears, when a selection is active.

I think one could reasonably say that this feature is both a bug fix and an enhancement. After all, all bug fixes are enhancements and all enhancements fix the bug of their absence. We use documented intention to tip the scale one way or the other, but that is completely missing for this feature and mostly missing, except for existence and the common, non-Python-specific meaning of words like 'search box', for everything else.