Jack's (Milo Ventimiglia) mystery will be mostly solved by the end of This Is Us season 3. The Pearson patriarch has been the beating heart of the NBC series, as much of his family's present lives continue to be impacted by his life and death. After the reveal of how he died back in season 2, the show's current outing delved deep into his life before meeting Rebecca (Mandy Moore) and his time in the Vietnam War with younger brother, Nicky (Michael Angarano/Griffin Dune). But as it turns out, that'll mostly be the gist of his story in the drama.
Immediately after it debuted in 2016, This Is Us began resonating with countless viewers all around the globe. Each fan has their own preferred member of the Pearson family, but one would be hard to find someone who doesn't have a soft spot for their patriarch. For the majority of the show, he's been portrayed as the ideal dad and husband - sacrificing his own wants and needs for the sake of his family. As the show progressed, it humanized him more with the reveal about his alcohol abuse and misjudgement of Nicky, but generally, he's still a poster character.
That said, as This Is Us moves forward next season, Jack will not be as prominently featured as he was in the last three years of the show. Series creator Dan Fogelman revealed to Good Housekeeping that much of Jack's arc has already been tackled by the end of season 3 and the focus will be spread out to his kids - Kevin (Justin Hartley), Kate (Chrissy Metz) and Randall (Sterling K. Brown). That doesn't mean, however, that he'll be cast aside, he'll still be an integral part of the narrative, but he just won't be the focus.
"I think a lot of the mystery of Jack has been kind of told by the end of this season. But it doesn’t necessarily mean it’s any less interesting to go and live with those younger families. I do think it’s fair to say that Jack remains at the center of the orbit, but some of the more mysterious or dramatic pulls of the series might start falling into the hands of some of our other characters in the back half of our series. The show is intended to be the expansive ways our lives evolve and connect us with other people. That starts happening more and more in season 4."
This backs up Fogelman's remarks during the recent Paleyfest where he talked about expanding the show - case in point: the upcoming introduction of Rebecca's father. The finale will also finally shed light on the mysterious flash forward scene which has something to do with the future of the Pearson matriarch. Between this and the ongoings in the respective lives of the Big Three, it makes sense that This Is Us will be slightly veering away from Jack.
So does this mean that fans will never see Nicky again? After the revelation that he's still alive following the Vietnam War - a detail Jack purposefully hid from his family, many were hoping that the show would get to spend more time with him, similar to how they did with William (Ron Cephas Jones). But if Jack won't be a central figure in This Is Us' future, it'll be tricky to incorporate Nicky back into the Pearsons' lives.
Source: Good Housekeeping