To acknowledge something that has been overlooked or unrecognized would be to:

To acknowledge something that has been overlooked or unrecognized means to bring attention to it in a way that recognizes its significance. The term "herald" is appropriate in this context because it conveys the idea of announcing or making known something important, especially something that has not received the recognition it deserves. When you herald a message or information, you effectively highlight it and ensure that it is acknowledged by others, often with a sense of importance or celebration.

In this case, the other words do not quite capture the essence of acknowledging something unrecognized. "Emphasize" typically means to stress the importance of something already acknowledged, rather than bringing attention to something ignored. "Celebrate" suggests a festive recognition, which implies prior acknowledgment rather than simply shining a light on something overlooked. "Proclaim" means to announce something formally or publicly but doesn’t inherently suggest recognizing something previously ignored. Thus, "herald" stands out as the most fitting choice for the action of acknowledging overlooked items.