Apparently it's because they're being given back the Falcon.
They have their guns drawn, though. It implies that they're taking it back by force.
It seems as if Daisy Ridley's character is piloting it on Jakku, and she's almost certain to be Han and Leia's daughter (if not theirs, then Luke's. The Natalie Portman resemblance is too strong for her not to be a Skywalker). Maybe Han let her have it and then some shenanigans cause it to fall into the Empire's hands and that's what draws Han back in.
Of course, that could all also be bullshit.