Sure, but lots of "X oil" products, especially where "X" is a flavoring ingredient, are oils from other sources infused with that ingredient for taste. "Chili oil" is not "oil pressed from chilis," it's "neutral oil flavored with chilis," and nobody expects otherwise or is confused. The complaint here isn't that truffle oil isn't pressed from truffles, it's that it's neither that nor oil flavored with truffles. Truffles are not involved.