I do understand that the climate in the "land of the free" is much scarier than here in Canada but I find the general paranoia about this kindof survey a bit extreme.
If non- and selective vaxers are misrepresented in such studies, it actually puts them more at risk of future problems. The reason govts can get away with mandating vaxs is that they have stats that show that people are highly vaccinated and epidemics do not seem too common. If they had the real rates, it might look a lot less convincing to force kids to get vaccinated. They also look at adverse reactions per million children receiving the vaccines. If non-vaxers are not included, it makes vaccines seem safer.
So, while there is a possibility that the government will be sending the men in black to inject your children in their sleep, the more likely scenario is that there are a bunch of exasperated medical sociologists at the CDC wondering why non vaxers keep hanging up the phone.