Still violates the VoP, even if against your will. Exalted feats section, and the expanded VoP description. Shapeshift qualifies you for Warshaper, which gets you quite a bit of nice things, and yes, you could enter primeval a couple levels earlier (2, iirc), but the power boost from WS 3 and 4 are worth the delay. Yes, shapeshift is redundant at that point, but it's largely irrelevant due to what it gets you from warshaper. It's also a fallback for when you have no Primeval shape uses left.