Season 3 ends with the Byers family (including Eleven) moving away from Hawkins, so the tagline makes sense for them. But it also hinted at Hopper's fate.
Fans had immediately theorized that Hopper isn't dead at the end of Season 3, despite seeing him apparently vaporized. This is because in the final moments of Season 3, set in Russia, we see a reference to an American prisoner who remains unseen. Pretty much everyone agreed it MUST be Hopper.