This is meaningless semantic drama over a meaningful discovery. From a biological and medical perspective, the collective term "organ" is pretty useless, if there is a distinct progenitor lineage. For the sake of a simplified explanation for the public, describing this discovery as finding "two organs" is absolutely fair.

A similar example: The melanocytes in the skin originate from the neural crest, not the epidermis. As a significant consequence, melanocytes share cell attributes with neurons. One of these attributes is the ability to infiltrate other tissues. Because of that, malignant transformation of melanocytes has vastly different consequences, compared to epithelial cells. If you asked your doctor why squamous cell cancer and melanoma have such different prognoses, describing your skin as effectively "two organs" would be illustrative and easy to understand, without getting into developmental biology.