I don't understand why people are so ready to believe this, without asking any questions.
Does any part of Concord scream Sony's most expensive game ever (and by a lot)?
Horizon 2 and The Last of Us Part II cost around $200 million for their entire development cycle. Those games are like top of the line for visuals, animations, etc, with hundreds of characters and cutscenes, and huge maps.
ProbablyMonsters has put out their investment numbers, and they don't support $200 million in development before Sony bought them. They got about $250 million in funding, and that is shared with two other studios who are working on their own games. Something like $150m would be the top end, and $100m is probably more realistic.
Spending another $200m in 18 months would also be pretty be absurd. It's not impossible, but that's at least twice as fast as the spending on Sony's biggest project. Spider-Man 2 was in development for 5 years, and about 3 of those years were with a full sized team. TLOU 2 was in development for 6 years, and about 3 of that was with the full 350 developers, with quite a lot of outsourcing. Sony's biggest games were spending $200m over a 36 month period.
The claim with Concord would blow that out of the water, despite having a very small core team. Firewalk is less than half the size of Santa Monica or Naughty Dog.
The idea that Sony fast tracked a game that they felt was broken, makes little sense.