this is an ideal example of "you know you need this, whitelist it" vs "this is always allowed". sites will definitely start messaging "whitelist or follow link from X" if default-block becomes popular, so I don't really think it'll break anything, tho it might be a bit more annoying.

(personally I get a small hit of joy every time I hit a site that is caught and blocked trying to do things it shouldn't, and vow never to return. it's better than it happening without knowing.)