Anyone that studies history knows that without Philip , Alexander would not exist nor would have the means to be "Great". So I will have to disagree, at least here in Greece Philip is as big as his son , if not bigger. But then Philip would have to stand on the shoulders of previous leaders , who stand in shoulders of other city-states inside Greece who stood in the shoulder of other countries , etc etc and etc. Overemphasising historical figures is for people that learn their history from Hollywood movies.
What really gets no billing is the Wars of the Diadochi. I'm reading Ussher's "Annals of the World" and its quite amazing all the twists and turns in the battle for the empire.
It is a bit weird that the headlines around this find are mostly being phrased like that. We studied both in school, and I had assumed they were both pretty well known.
I guess for a headline-writer, though, "Alexander the Great" has near-universal recognition, while "Philip of Macedon" doesn't have enough to assume that a general audience will have their eye caught by the headline. So it ends up with this slightly dumbed-down phrasing.
From reading the article it's obvious that they have tons of very detailed information on Philip II. The only part of this title that fails to convey this is the title.