It's changed because those files were made a very long time ago and they did not know any better. Or if it has been done in recent files, then they just don't know how the ECU works.
There is no reason to ever change function monitoring maps, they do not take the actual engine calculation into account.

Simply put the ECU does not use them to run the engine. They are theoretical values used to check for bugs in the internal algorithms and hardware of the ECU.
If an error detected an ECU RESET or complete disable of affected module occurs.
Unless you are completely rewriting the code of ECU modules or for example changing the processor to a different type, you would never need to touch the monitoring concept.

This is no longer the case in e.g. MED17 where it works completely differently.

I mean the FR is public domain at this point, all this information is found there.