Considering the Kor´Kron not even there, as you said, would be a major flaw on out part. It would mean ignoring facts from the lore, the Wrathgate incident and the following overseeing of UC by the orc guards.
The House does consider the orcs there and we know why they´re there.
The Undercity is being watched over, thus we had to move the House´s operations elsewhere, to a base we had long ago the Wrathgate even happened. The House Keep has no Kor´Kron guards in it, only the guards the House has appointed itself, nor will any orcs ever be allowed there.
Basicaly for us that means that we have to behave in front of these guards, but we can be our cheerful, happy selves where they aren´t able to see or hear us.