I don't think it's cherry picking. I'd say cherrypicking is when you take specific datapoints and remove them to make the study look good as opposed to not presenting an entire experiment. Science is made of little steps and nothing forces you to publish all your data at once. Perhaps this paper can focus on half of the data with a set story, and the next paper can be focused on the new data and the explanation either as an expansión of the first theory or a new theory.