In another review / guide on Steam someone remarked that "Because of his own internal fears of something that Coda likely finds comforting, he attributed his own internal feelings to Coda's intent." I think, in one sentence, you have really the whole story.

Love my introspective metatextual boys. Very Charlie Kaufman. Though I will say I first played this in 2015 and I couldn't for the life of me recall what this was about until I played it again now in 2024.