This sounds like great advice, but a minor nit: I never saw anything like this when I was practicing karate, or heard of a karate dojo that did this.
You didn't do pushups in your karate dojo?
Stretch? It may not be specifically called "preventive training" but I've not seen a karate or TKD dojo where some part of every session was devoted to a bunch of exercises that - while called 'warm up' were also 'conditioning' - or 'prehabilitation' or....
Not that I've been to a lot of karate or TKD (one or two of each) but we sure used to do a lot of stretching, pushups and (it was a long time ago) situps in judo...