The microexpressions in this scene absolutely destroyed me. You can almost see a weight is lifted from Titus' chest, it's almost like he is close to tears. His voice is barely controlled, as if it would tremble if he let it. His worst fear, his greatest shame that he internalized for 200 years, was not true. His brothers did not forsake him. His commander and friend Calgar never stopped trying. His family never believed him to be a traitor.
This is the closest this universe gets to finding out you are, indeed, loved. It's a shooting game about stomping xenos heads, but goddammit, it's also about love and loss, regret and bitterness, paranoia, and trust. Titus regained his family. How he must have grieved, how he must have through himself into the deathwatch, desperately seeking a new brotherhood in his disparate comrades, torturing himself in the hopes of regaining a convoluted idea of redemption.
In the world of Space Marines, Calgar might as well had clutched Titus to his chest and told him "I never stopped thinking about you brother, I knew you were always innocent, I am so sorry I couldn't bring you home sooner, please, forgive me."