(Like what to do with your hat in an evacuation - I kid you not).
That was probably so you would be noticed as you "directed passengers away from danger". Most uniformed officers wear hats to make them conspicuous in the crowd. (e.g. police)
The sort of all-encompassing SOPs we are talking about are a phenomenon of only the last fifteen years at most.
Crikey! Where were you hiding?
We had adopted NASA CRM training by the mid 80s.
https://ntrs.nasa.gov/archive/nasa/c...9800013796.pdf