I finished it today myself. Normally, I love these kinds of games (where story/characterization are put way before any real gameplay, per se), but this one left me a little cold.
I'm not sure why. Maybe it has something to do with how true or not the story is, as you say. Maybe I didn't really connect with Davey (though I'm not convinced you're supposed to). Maybe something else.
I certainly appreciated what he was trying to accomplish, but somehow it didn't really click for me as a whole. There were moments that really connected, though. As an actor/writer myself, I certainly was intrigued by the broken machine and who art is being made for, etc. Maybe I've covered that ground a little too much.
But as to your question, I suspect there is a grain of truth, but that it's been carried to an extreme. There may have been an impetus for Coda, but at best, I'd imagine a discussion or argument got pushed through the fictional wringer. At worst, he's totally made up. More likely is that Coda is a hodgepodge of different people.
That said, I doubt the games within are designed by anyone other than Davey himself (though he may have been inspired by others), if only because that would create all kinds of potential legal hassles.
True. Later I spent some time reading reviews, and the legal implications if this were entirely truthful occurred to me.
The games could be of Davey's design, but the story could be based on something that really happened. Either way, whether he's telling his own story or creating fiction, it's hard to feel sorry for him/his character.
That being said, there are still grains of truth within the game that could apply to a lot of creatives (the dips in the creative grind, the depression and frustration when your ideas run dry, and even the idea of craving personal validation).
Though a lot of reviewers had a beef with the lack of choice in the narrative, unlike The Stanley Parable, I liked each game for what it was; it did feel like witnessing the creative process. I could relate to or understand a lot of what was presented; I just didn't care for the ending.