One at at time I deleted EXIF and then checked with ExifTool and EXIF data was gone. Then IPTC and ExifTool indicated IPTC was gone. However, PM was still indicating IPTC data present. It apparently was XMP data because when I deleted that, PM did not show IPTC data any longer. BTW, this was on a jpg file.
I don't know if this is a bug or a feature...or perhaps depends on your configuration of IPTC/XMP under preferences.
Jerry