Yes! When you link images instead of embedding them in Publisher, the program will still embed the images into the pdf file with the original resolution in tact upon export.
I am using the same images multiple times in my Publisher document. Because each instance of an image was embedded individually in the Publisher file, each instance was also being embedded individually into the pdf file upon export. When the files were linked in Publisher instead of embedded, the program realized it only needed to embed each image file once when exported, instead of embedding every instance of the image in the pdf file.