Just wanted to chime in here and say that yesterday I successfully swapped the bench seats on my 2011 Traverse with bucket seats from a 2013 Enclave.
Some caveats if anyone still wants to do the same thing.
1. Try and use an impact wrench. Of all the times for mine to not work, this was it. The bolts used to keep the bench seat on the floor could not have been on any tighter and I had a helluva time getting them off manually with my ratchet. If you don't have an impact wrench I'd suggest spraying some PB Blaster catalyst on each bolt and letting it sit for while before attempting to loosen the bolts. ou may find you'll use muscles you didn't know you had.
2. You'll need to cut out some carpet on the driver side in order for the right side rails of the new seat to fit and be able to be bolted down. I recommend putting the new seat in place, then using a piece of chalk on the carpet to outline where you have to cut. Cutting the carpet will also expose the "filler" bolts in the unused holes. You'll need a Torx 50 bit to remove these bolts.
3. In total, the 2 bucket seats use 3 more floor bolts and washers than the bench seats. You can get these from your dealer, but ones from your local hardware store will suffice.
4. The plastic trim panels that go over the seat rails won't fit exactly. I needed to trim off some plastic on the underside of them with my Dremel in order for them fit. Also, if you care about how they look, the "outside" pieces...the trim pieces next to the doors work fine, but you'll need to replace the "inside" trim pieces for both seats, as the ones designed for the bench seats don't look quite right. I haven't been able to find them online so I may have go to the dealer for those.
5. Factory floor mats from the bench seats no longer fit properly.
6. There will be a "hole" in the carpet from where the old rails from the 2 bench seats met. Haven't figured out how I'm going to tackle this yet. I may just fill it with whatever foam I can find the put the weathertech floor liner over it and nobody will know the difference.
In the end, aside from getting the bolts off it was a pretty easy and straight forward job. If anyone has any questions, feel free to ask.