thats just a fan theory and I don’t think it’s true. For one thing you very blatantly talk to his spirit as a stalfos in twilight princess and it seems clear he made it to adulthood. Also I’m pretty sure Miyamoto has officially confirmed that Termina is a real place and not in Links sunbinscious as a result of that theory. I do believe that the events of the game had a strong effect on that links mind and contributed to his insanity. And some aspects of the game may have been exaggerated in his mind. I do believe that the games levels may represent the stages of grief but I think it’s over losing Navi rather than accepting his own death. As an aside though the game does conjure a feeling of existential dread for me. One of the darkest games ever made probably and yet most of its darkness is symbolic so I didn’t notice when playing as a child.