No, the people who say they have no internal sense of gender are mostly cis people. They're just fish who don't know they're in water, as a bad analogy.
Having no internal sense of gender *is* what agender is, though! U can't tell an agender person they're just a fish who doesn't know they're in water; that's pretty invalidating. Reading the /r/agender subreddit really backs this up.
I mean, I agree there are people who are agendered. I'm highly suspect of your poll, and I know from talking to a lot of cis people who haven't deeply considered their gender identity that they don't think they have one.
There's a difference between having no internal sense of gender, and having an internal sense of being non-gendered. The latter probably count as trans, but the former probably don't.