That sounds like a Fagan review. I haven't been involved with one either, but I think some of the forces that drove people to do them have been weakened.

When you are shipping code that you won't be able to update easily (i.e. cheaply), you try to remove as many defects as early in the process as possible. CI/CD and web delivery seem like they would blunt the motivation to go through a Fagan review for most software developed these days.

I would imagine that some form of this still happens in safety-critical systems (or more likely the state of the art has advanced from this).