But I’m not entirely sure what it means.
Who doesn’t trust their palate? Does anyone say, “mmmm, I really like that Pinot Noir but give me the Zinfandel. I hate it but I must be wrong.” It seems like a bit of advice that no one needs, like your mother telling you to be careful.
Perhaps the advice is meant to soothe the feelings of people who think their own tastes are unsophisticated and out of step with the experts. But I rather suspect it is meant to signal that the speaker is on the side of the audience against those snobs and trend-chasers–because she has something conventional to sell.
At any rate it is bad advice. It assumes that we have nothing more to learn. That there are no experiences out there that we might have to stretch for in order to understand. “Trust your palate” is a ticket to boredom.
Of course, drink what you like. But keep in mind that what you like is a very small part of what there is, and there are likely plenty of treasures that you will never discover if you stick to the tried and true.