I tried that flavor last weekend. I think you're on the right track because I really thought it tasted like
a cheeseburger. The only difference for me is that I thought it tasted like one I'd eat at a family picnic or bbq. Not only did I taste ketchup, but also mustard, pickles, onions, and just a hint of smokey.
I think this is a fun marketing gimmick on their part. I even visited the website and won a free Doritos t-shirt. That one had to do with the Flavor Competition promo from earlier in the spring.