That's not true. I remember TV Spots including vampires as well. Everyone knew the kind of movie it was at the time. It was heavily marketed in that direction. Same with Terminator 2. It's fun in the movie on it's own. People who were excited to see those movies knew what they were going into them. It was all over the posters, trailers, TV spots. Source: I was there.

I understand some people may have gone in blind at the time. But it was pretty difficult to avoid the advertising for it at the time if you were into that sort of thing.