If you're an ecommerce based site then change is always good for the customers.
There can be categorization of pages based on frequency of changes. So changing content is neither good or bad but can shift you from one set to other. Different set may react differently for your set of page ranking attributes.
I think there can be topics that can be marked dynamic or static too based on machine based study (that Google is good at) of a sample of pages on that topic.