It is false! As mentioned in the edit, a positive answer to this question would imply the Lyubeznik numbers $\lambda_{i,j}$ of a projective scheme are independent of the defining projective embedding for $i \geq 2$. The recent preprint
https://arxiv.org/abs/1803.07448
by T. Reichelt, M. Saito, and U. Walther, gives counterexamples (even equidimensional ones) in characteristic zero.