I noticed they put wrist guards in there, better to learn to fall properly. While learning I fell awkwardly once, and maybe the wrist guards I was wearing saved my wrist, but the reinforcing bar inside them cracked a rib instead
Related: if your jacket has chest-level pockets, never put anything hard in them. On two separate occasions I have broken ribs by doing that. The first time it was my phone (which amazingly came away unscathed), and the second time was a chapstick.
A cracked rib is significantly less bad than some of the wrist/hand injuries I’ve seen from snowboarding. One of my friends pushed the radius and ulna either side of his wrist.