The Short Version
Heidegger critiqued the Western metaphysical tradition but did not oppose all metaphysical claims in principle. The most authoritative scholarly sources — including the Stanford Encyclopedia of Philosophy and the Cambridge Heidegger Lexicon — describe his project as a transformation and re-grounding of metaphysics, not a wholesale rejection. He pursued a "metaphysics of Dasein," advanced substantive ontological theses, and acknowledged that we are "always already within" metaphysics. The claim's universal scope fundamentally misrepresents his philosophical position.