That applies to rest only. Basically, it allows the company to contact you once so they can notify you of a schedule change. It doesn't apply for days off, unless it is rest on a day off before you start a trip.

I'm in the middle of about 12 days off so there is no duty or rest for them to worry about.

The definition of rest in the contract seems to make this even muddier if I'm reading it right so I understand your point but the definition of day off makes sense. If it ever happens to you file a grievance and see what happens.