If you look at other seals (axle seals, crankshaft seals etc) you'll see that they too have beveled lip facing in. The reason for this is that when pressure is applied the beveled lip pushs up against the steel surface it rides on. More pressure = more push on sealing lip. If the filter is tight then there's no way the beveled lip can do anything but make a tighter seal.
GOD bless America!