This feature exists in Lightroom Classic. It is sorely missing from Lightroom CC. Lightroom CC also needs a feature to mark a detected face as not a face - it often detects random pixels as a face, and constantly re-detects it.
I'm new to Lr CC so maybe I'm missing this feature that I thought was in Lr Classic. Is there a way to identify a person in the photo when the facial recognition did not recognize additional faces (add people in the photo)?