The relatedness is very much up for debate though. If i like an article on a website, then later on that website publishes something else which is only related because its on the same site, does that mean facebook can re-use my like for the new page? Not only would i need to vet all the current content to see if there is something that i don't agree with, i would need to trust they would not post something horrible in future and have my name attached to it under a related post.

The unsophisticated user won't read "related post" because it isn't noticeable. There's no clear differentiation between a recycled "like" post, and one that you physically like. They look almost identical.