It's not; I think you're parsing 'expect to use' differently than intended.
"sites that you expect to use such features on"
This means "sites on which you expect to use such features"
Not "sites where you expect them to use such features"
The preposition is key to having you be the one using, not the site. It doesn't have to go on the end, perhaps, and you could rewrite the sentence without that preposition, but simply removing it would leave you with an entirely different meaning.
