Did you read the article? Rome gave its new district the name that the region had had since at least Herodotus’s day. Your argument is like saying there were no Americans before the United States was created—the region had been called America for centuries.

And your insistence that the original area called Palestine is the only true area is like insisting the only the original 13 states can be called America. Words have different meanings in different contexts—New York can be the city or the state.