A lot of armchair engineers here...
Out of curiosity, how many of you have taken a class like thermodynamics or heat transfer?
The heat pipes not in contact with the GPU are fine, if indeed the pipes are in contact with each other. This is the big caveat, as air is a very poor heat transfer medium. However, a
little space between the pipes
can work. Thermal expansion of the pipes will occur, but the CTE of copper isn't much, especially below 100°C.
If the pipes are in contact, though, they will conduct almost as much heat away from the source as the heat pipes that are in direct contact with the GPU (well, in direct contact with the thermal paste).
Here is a quick FEA of a simple system like the card. This assumes contact between the pipes, however there is a fillet around the edges so it isn't full contact. I didn't take a screenshot, but the top view shows a slightly different gradient on the end pipes. The middle pipe has the most heat the farthest out towards the extensions, where the cooling takes place.
Any questions, let me know...