OP specifically pointed out that it's well documented. Every program makes tradeoffs, and I don't think anyone in this thread implied that because Postgres made this one it's unstable or bad.
The specific behavior of Postgres isn't the FUD, the FUD is the speculation that this is what brought down Roblox for multiple days. As others have mentioned, we don't even know if Roblox uses Postgres, and yet we're diving deep on how an edge case of Postgres brought down Roblox. It's the speculation that I think is FUD.