I wouldn't make those changes based on just to Wiki-articles. The people (my guess
Havard) who came up with the Yngling name for the game, know probably much more about Norwegian history then we do.
Why should he have a claim ? William was the rightfull ruler of the duchy of Normandy, Philip had no claims on it at all. The French kings were weak at that point and they were not more then the 'first among equals'. A French king couldn't just revoke titles from his vassals, just because he felt like it. Anyway, Hårfagreætta is the modern Norweigian name for they dynasty that ruled during the CK era. We've used less precise sources in the past.
And in game sooner or later the French and English kings will start a war over Normandy.