I believe that you are unfortunately correct.
It's not that they're going to come hunt down my friends who might have undeclared "assault weapons" or "high capacity magazines" - it's that they might get discovered secondarily to another issue.
I had lots of conversations with my friends when that law was announced, prior to it taking effect. My first reaction was to go buy a couple of ARs - because I didn't have any. And after a lot of consideration, I declared them. Which means that the state of CT knows that I have, (or had), them. In my case they already knew, because I bought them from FFLs, so 4473 and DPS-3 forms were filed.