It makes perfect sense to me. Like many of the processes in the body there is an optimum level and duration of the hormones and chemicals we need to live and enjoy life. Just like insulin, estogen, serotonin and thyroid, etc. We either don't make enough of them, or too much, or release them at the wrong time or wrong amount or have an internal resistance to using them properly.
By releasing most/all of the stored dopamine triggered in a sugar surge, it will take some time to replenish the dopamine. Meanwhile, we want the dopamine rush again and continue to try to recreate it by eating more sugar. There's just no more dopamine left to release. Its the general problem with other addictions - the inital rush and then trying to get it again and again.
I am not shocked at finding the connection between sugar and dopamine. And soon, they will probably find a connection between fat and some other brain chemical. And this will support the rumors of manufacturers making food addictive. In my skepticism, I believe they have done research on what triggers the optimum reactions when eating their product and use it to trick us to eat more. It is up to us to make the choice to eat their products.