It appears that Facebook has made a small tweak as a part of the new news feed, which is currently in the middle of a slow, delicate rollout.
It appears that Facebook is putting an obstacle between users and their ability to unlike pages that they follow. Well, Facebook hasn't really added anything - they've removed a shortcut which pretty much amounts to the same result.
Anyway, users of the new news feed are no longer given the option to unlike a page directly after hiding one of the page's post inside the news feed.
After hiding a post in the old new feed, here's what it looks like:
Now, here's what it looks like with the new news feed:
Notice that the unlike link is gone?
Now, if a user wants to unlike a page (and they very well might, since they're hiding posts from that page), they'll have to visit the page first and unlike it from there.
This could simply be an accidental removal - the new news feed is still in beta. But if we assume that Facebook has done this purposefully and permanently, it suggests that Facebook is doing all they can to keep people liking things. Because without all of those likes, how would Facebook know anything about users for targeting purposes? Sure, a user can hide a page's posts - but if that like remains then Facebook retains that specific crumb of data. And every little crumb matters.
As Inside Facebook points out, this could also lead to page owners seeing less reach from their posts, even though likes seem to be staying stable or even increasing.
I've reached out to Facebook and will update when I hear back.