I am (very slightly) curious if they'll remember to simulate the Columbian Exchange.
By default the New World is all maize OR potatoes. Later on there should be rice in the Lowcountry and Louisiana (nowadays in Arkansas), potatoes and wheat in the North, potatoes in Europe of course, but maize remains the dominant crop in the South.
Paradox has always completely sucked at both simulating realistic trade and even the inaccurate trade theories of its time. I don't care about their games anymore so I haven't paid any attention to how it's supposed to be done now, but EU4's particularly bad decision was living in a bizarro world of reverse-mercantilism where wealth is created only by importing and trade just kind of flows to designated areas without any reason.
What is a lot more realistic, mercantilism or no (and mercantilism is what a player will naturally tend towards anyways if they're powergaming, I think of EU4 - MEIOU and Taxes - as being about the story of state formation), is representing trade as binary exchange where trade value goes up the more variety of scarce things you bring the other party. Like a diminishing return for each unit they have (from both you and deomstic production).
EU4 is also a golden age for "triangular trades," where you build a more profitable trade route by having it loop on itself in such a way that every transaction is part of a series of swaps that lets you keep your cargo hold full (maximum efficiency) while accumulating value. Like manufactures --> furs --> porcelains (New England --> Pacific Northwest --> China) or manufactures --> slaves --> sugar (Europe --> Africa --> Caribbean). Some other trades I'm pretty familiar with are things like the Indian fur/deerskin trades. Indians were integrated into the global economy as producers of furs and slaves that were basically dependent on the outside world for everything else (that wasn't shitty stone tools).
This is the kind of thing that would make trade much more interesting than the current garbage.
For EU4's time period I think it's fine for it to focus more on exotic luxury goods.