Your claim seems important if true. My personal tendency is to preserve data where I don't understand what's going on, and my impression is that lots of data is stored in the biochemistry itself... precisely which receptors exist, how deeply they're embedded in membranes, what kinds of fatty acids a membrane is made of, and so on. Dendrites and axons engage in chemotaxis where they follow genetically programmed ion and/or protein gradients. If you wipe out the chemical gradient information then how do you know what sorts of ways that the dendrites should regrow in the weeks and months post-resuscitation?

A divergence of opinions here could be due to different assumptions about what kind of knowledge will be available in the context of resuscitation. If your resuscitators have vast and deeply tested knowledge of the operation of many kinds of brains, then they might be able to mock up plausible values for all the chemistry and produce someone "similar enough" (and its certainly better than nothing but a bunch of letters and photos and Madeleines). If they're doing this for the first time in a sort of "1950's plucky engineer mode", then I would naively suspect that plastination pushes someone closer to information theoretic death than even membrane-damaging no-vitrification cryonics of the sort that was standard operating procedure in the mid-1970s.