Long Live the Confederation!
Ah, this part was missing in the wing commander franchise: a link between WC1 and the tiger's claw's destruction, great!
I don't think that's really been missing - the Wing Commander I & II Ultimate Strategy Guide has a narrative that runs through both events. From a dramatic standpoint Secret Missions 2 was (clearly) written as a prologue for Wing Commander 2 - it exists to introduce you to all the story concepts created for WC2. Almost everything in the game is some conscious setup, from introducing new characters (Jazz, Doomsday, Thrakhath, Spirit's fiance) to introducing important concepts (Angel becoming emotional over Bossman's death, Paladin 'retiring', Angel becoming a Wing Commander, etc.) We also recently learned that a novel about the destruction of the Tiger's Claw was planned but not developed - presumably it would have followed Hunter after the end of Freedom Flight (which is itself another clear setup for WC2).