The more I think about this feature, the more I'm convinced that it also needs an option to automatically invalidate or delete the entry when the specified date arrives.

"Default content review frequency per catalogue"

The custom field mechanism has been utilised so this also works for all content types supporting custom fields - i.e. you can specify individual default review frequencies for each default content type.

"Notification hook for staff, make it a discussable one"

Not been made a discussable notification, for technical reasons (plus it's borderline whether this would or would not be bloatage).

I find it funny you used a page about diarrhea as a demonstration. Nonetheless, this was an excellent idea. I use this feature all the time.