True..some Genetics academic journal did some genetic study and found that the myth of People in Southern Italy and Spain having a bunch of Arab ancestry is wayyyy overblown and it is true for certain villages or provinces but not the country as a whole...the exception..not the rule...like you said.
Their is kind of a difference between North and South Italy's ancestry..but it's not from the Moors, or North Africa...the South is more descendant of Greek settlers and the North Celtic and Germanic...but there is Germanic in the South too...the Normans(descendants of Vikings) are a good example...they held shit down down there..and for way longer than the Moors ever did, Lombards are another example...My moms must be from that since she is Italian, family from the South, and they all have/had fair hair, eyes, and skin...not the typical Southern Italian, lol.