>I don't see this happening at many (or any) companies
It's exactly how the process works in the UK, at least below executive levels. Not least because it's the easiest way to obtain the proof of incompetence required to demonstrate that the firing was done fairly.
In the UK employees don't have any right to challenge for unfair dismissal until you have been employed for one year - up to then you can be fired with little process.
Not quite - if you are dismissed for an automatically unfair reason (mostly to do with discrimination, but also some others in there like having to serve for Jury duty) then there is no qualification period.
As of April this year the limit has also increased to 2 years.
It's exactly how the process works in the UK, at least below executive levels. Not least because it's the easiest way to obtain the proof of incompetence required to demonstrate that the firing was done fairly.