What do you mean by 'content' here? The basic narrative each model tells about the economy?

Right. Plus most undergrad models have an analog in grad macro, i.e. the AD-AS model and the New Keynesian model, or Quantity theory of money and a basic cash in advance model.

The big difference between the models I learned in undergrad and the models I learned in grad school was that in undergrad, everything was static. In grad school, the models were dynamic

True in general. Some intermediate macro courses use a two-period framework to explore basic dynamics. Williamson's textbook does this.