That is a very good question. I must admit I do not know.
My first hunch would be that the Kaaba is inanimate. So it should be OK to make a replica of it.
Some side information:
The Kaaba is a human made structure...and it is rebuild several times throughout the history.
So the building itself (used stone, wood, bricks, etc) has zero religious value. Theoretically it could be totally stripped down and be rebuilt.
The important parts of the Kaaba are:
-its exact location
-the black cornerstone al-Ḥajaru al-Aswad.
So, making an exact replica wouldn't be that dramatic would be my guess, because It would be just a replica of a building.
It starts to become a different story when people start to pray towards it...that would be haram of course.
Again, this is just my own thoughts...I am not an expert on this.