The answer is clearly no. But a variety of sources - some on the left, some on the right - took the context of a legitimate question and teaching moment and turned it into a caricature of itself, making it seem as though a Portland principal had deemed the sandwich racist.
The point was that you need to understand the cultural context in which a conservation is taking place. If the person on the other end knows nothing about a peanut-butter-and-jelly sandwich, it would be wise to try to communicate in a way that will highlight some of the similarities you share. Businesses do it all the time in multiple ways to reach a varied audience because they want to sell cars and toothpaste, or whatever, to as many people as possible and know the first step in that process is to effectively connect with members of the target audience.
What's wrong with teaching students to do the same? When diversity courses are done well, that's what they do; they don't apply simplistic, overly-used labels to generalize.