You didn’t really answer my question. There is a considerable difference between fine art and graphic design, and my answers would differ accordingly.
I’ll answer assuming your professor is referring to graphic design.
The purpose of graphic design is visual communication with a target audience to achieve client objectives. Aesthetics plays a role, but it’s entirely subordinate to the function of achieving the end goal (in which aesthetics usually plays a part).
Trends in graphic design are typically technical (new technology creates new possibilities) or aesthetic (different fads come into vogue). Judging by the question, I’m guessing your professor was referring to aesthetic trends.
Aesthetic trends should largely be observed, then tucked away in case they’re useful for the project at hand. However, most of these trends are more about designers vying to make the prettiest, coolest, and best-looking stuff and winning awards rather than achieving client objectives. And as I implied, pretty, cool, and good-looking should be subordinate to functionality. There’s an overlap, of course, but it’s relatively infrequent that those overlaps involve trendiness.
Most real-world projects do not lend themselves to the latest aesthetic trends. Instead, the approach to any real-world design project requires an approach specifically targeted to the objectives of that project. The end product shouldn’t look dated, but it’s not often that trendiness significantly contributes to the end product’s effectiveness.
Besides, designers should be trendsetters, not trend followers.
These considerations don’t change: budgets, clients, technology advancements, return on investment, social changes, etc, If your instructor is focusing, instead, on aesthetics, as I suspect, that’s too bad because in the business world visual communication and achieving client objectives are the objective (yeah, I’m repeating myself).
Nobody knows. Anyway, it doesn’t matter because whatever comes along will simply provide more things to consider in the overall puzzle of visual communication. Anticipating technical changes, job market shifts, and career paths are relevant trends to consider. How graphic design will look in 10 or 20 years is not.