Warning - Big Spoilers for Death Stranding ahead.
Because the cast of Death Stranding is so small, it is up to the main characters to carry the bulk of the story. Malignen, AKA "Mama", is one of the inventors that provides Sam Bridges with his gear and whose relationship with her sister Lockne is a core component of the narrative. Likewise, both Heartman's search for his dead wife and daughter and his study of the Beach are integral to the understanding of the phenomenon known as the Death Stranding. All the main characters in Death Stranding wear many hats, with none more so than Die-Hardman.
John Blake McClane, AKA Die-Hardman, is the Director of Bridges and is partially responsible for sending Death Stranding's Sam Bridges to reconnect what's left of America to the Chiral Network. While most of his contributions to Sam and Bridges are mostly done offscreen, he is nevertheless one of the few people that Sam has a genuine connection with. But seeing as the end of the first game put Die-Hardman in a more passive position, there is a likelihood that he won't be as prevalent in Death Stranding 2.
Die-Hardman's Past Actions Have Earned Him A Very Powerful Position
John McClane served the U.S. Army Special Forces under Clifford "Cliff" Unger before working for Bridges. After discovering that his former commander's son was being subjected to experiments regarding Death Stranding's bridge babies without consent, John aided Cliff in rescuing the child and escaping the Bridges facility they were being held in. The attempt failed, with Cliff and his BB son being murdered by John at the hands of Bridget Strand. To cover up the incident, John was declared dead and was given the name Die-Hardman along with his iconic mask to hide his identity.
Die-Hardman would continue working as the leader of Bridges and guide Cliff's reborn son Sam on his journey to rebuild America. Sam's journey eventually leads to Die-Hardman's attempted murder of Amelie who he discovers is the extinction entity responsible for bringing about the next Death Stranding. After his plan is thwarted at Amelie's Beach by Cliff, Death Stranding's Die-Hardman breaks down at the loss of his former commander and Amelie before taking up the mantle of President of the United Cities of America.
Die-Hardman Might Be Absent In Death Stranding 2
Save for a few other characters, Die-Hardman is Sam's constant companion and provides players with helpful advice and insights into the world of Death Stranding. He gives tutorials on how to do things like building structures like Death Stranding's Zip-line, leaving likes on other players' creations, and collecting important materials for the creation and restoration of said structures. Lore-wise, he provides information about the state of the world before and after the Death Stranding occurred. If it wasn't for Die-Hardman's hand-holding at the beginning, players would be lost.
Should Die-Hardman be the President of the United Cities of America by the events of Death Stranding 2, his role as a guide could be diminished. He would have far more responsibilities, considering he would be both the leader of a large logistic company like Bridges and the overseer of an entire nation. Sam Bridges would also have a handle on the world and how it works by this time, requiring less input from Die-Hardman regarding his adventures. Unless Death Stranding 2 has a new president, protagonist, or another important mission to complete, it wouldn't make much sense for Die-Hardman to play a very active role in the game.
This is a shame considering Die-Hardman's actor, Tommie Earl Jenkins, did a great job of portraying the stoic yet vulnerable leader of Bridges. He seems to genuinely love playing the character, and it would be a waste to relegate Die-Hardman to a more supporting role in Death Stranding 2. Should Kojima Productions decide to sideline Die-Hardman, it should properly justify his absence and provide players with just as compelling characters to fill the void he leaves behind.
Death Stranding 2 is currently in development for PS5.