User should preferably be the one in control. Which simply means, there should be a way (now that could be as intended by the interface and the context), for the user to know what is going on - and if needed, alter that.
I like Medium's approach as a related example - For a signed in user(meaning to say for whom there is personalisation possibility) - home page shows Top Stories for you, but with a clean close button. See screenshot -

Now, if I possibly intend to check other/all stories, I hit close, and it loads the default set (in some order of course). So the essence is user being in control.
In most cases, expected user behaviour could be of not opting to close, but just knowing that I(user) am in control - makes the user feel better.