The linked article asks "So where did this notion that Molly Malone belongs to Dublin — and might even have been a real fishmonger from Fishamble Street — come from?" and offers the answer "Where many questionable things come from: the minds of people who work in marketing." Marketing may be responsible for the notion that Molly was a real person, but the Dublin connection is in the song's first line, presumably put there by the songwriter (apparently one James Yorkston).

"... the Floozie statue ..."

Hang on! Surely the Floozie was the one in the jacuzzi in O'Connell Street, and Molly is the tart with the cart.